Getting Started. MAN 0101 Issue1.3 August 1997

Transcription

1 Getting Started MAN 0101 Issue1.3 August 1997

2 Malvern Instruments Ltd. 1995, Malvern Instruments makes every effort to ensure that this document is correct. However, due to Malvern Instruments policy of continual product development we are unable to guarantee the accuracy of this, or any other document after the date of publication. We therefore disclaim all liability for any changes, errors or omissions after the date of publication. No reproduction or transmission of any part of this publication is allowed without the express written permission of Malvern Instruments Ltd. Head office: Malvern Instruments Ltd. Spring Lane South, Malvern. Worcestershire. WR14 1XZ U.K. Tel + [44] (0) Fax + [44] (0) Windows is a registered trademark of Microsoft Corporation. Tygon is a registered trademark of Cole Parmer Instruments Company Limited. Printed in England

3 CONTENTS Contents Chapter 1 - Introduction to this manual Welcome 1-1 Systems covered by this manual 1-1 Access to the instrument 1-2 Assumed information 1-3 Windows terms 1-3 Menu commands 1-5 Where to find information 1-5 Other reading 1-7 Chapter 2 - Getting to know your system Introduction 2-1 A typical system 2-1 The optical unit 2-2 The transmitter 2-2 The sample area 2-4 The receiver 2-7 Differences between the long and standard bench Mastersizers 2-9 The Malvern software 2-10 The Mastersizer program group 2-10 Finding your way around the screen 2-11 Modes of operation 2-15 Menu mode 2-15 Easy mode 2-15 Program mode 2-16 Getting help 2-16 G E T T I N G S T A R T E D Page i

4 CONTENTS G e t t i n g S t a r t e d On-line help 2-16 The F1 Function key 2-17 The Help menu 2-17 The Help window 2-17 Jumps and Popups 2-18 Status line 2-19 Reporting Problems 2-19 Chapter 3 - How the Mastersizer works Introduction 3-1 What does the Mastersizer do? 3-1 How does the Mastersizer do it? 3-2 How to make a measurement 3-4 How to analyse the measurement data 3-6 The analysis model 3-6 The presentation 3-6 Calculating the result 3-7 Viewing the result 3-8 Saving the result 3-8 Chapter 4 - Making a measurement Introduction 4-1 General measurement advice 4-1 Sample preparation 4-2 Cleanliness of the optical system 4-2 Choosing a range lens 4-3 Size range of your sample 4-3 Sample dispersion method 4-5 As general advice 4-5 Page ii M A N

5 CONTENTS Avoiding lens cut off (Vignetting) 4-5 Always measure a background 4-6 Making a measurement 4-6 Instrument preparation 4-6 Document the measurement 4-8 An introduction to the measure windows 4-8 Align the system 4-10 Take a background measurement 4-11 Add the sample 4-11 Measure the sample 4-13 Chapter 5 - Analysing the measurement data Introduction 5-1 Choosing the correct analysis mode 5-1 Choosing the correct presentation 5-3 The Malvern presentation grid 5-3 Methods of selecting a presentation 5-5 When is the presentation important? 5-6 Selecting a presentation 5-7 Special Presentations 5-8 Calculating the result 5-8 Chapter 6 - Viewing and printing the results Introduction 6-1 Views 6-1 Reports 6-3 Overview of the standard views and reports 6-4 Understanding printing 6-6 Selecting fonts for graphs and tables 6-7 G E T T I N G S T A R T E D Page iii

6 CONTENTS G e t t i n g S t a r t e d The Graph fonts 6-7 The Table fonts 6-7 Installing and selecting a printer 6-8 Changing print settings 6-9 Printing from the Mastersizer 6-9 Chapter 7 - Interpreting the results Introduction 7-1 Fundamental concepts 7-1 Results are volume based 7-1 Equivalent spheres 7-2 Derived distribution parameters 7-3 Understanding the tables and graphs 7-4 Chapter 8 - Automating the process Introduction 8-1 Setting up a sequence 8-1 Chapter 9 - Sample preparation Introduction 9-1 Representative sampling 9-1 Considerations for dry samples 9-2 Considerations for wet samples 9-3 Choice and preparation of the dispersant 9-3 Surfactants and admixtures 9-5 Surfactants 9-5 Admixtures 9-6 Slurries 9-6 The use of ultrasonics 9-6 Page iv M A N

7 CONTENTS Samples with unstable concentrations 9-7 Bubbles 9-7 Summary of sample preparation 9-8 Chapter 10 - Advanced result processing Modifying results 10-1 Killing channels 10-1 Killing data channels 10-1 Killing result channels 10-3 Using the Kill cursors 10-4 Shape correction - Changing the size calibration 10-4 Extending the result 10-6 Transforming result type 10-7 Blending results 10-8 Multiple modifications 10-9 Tromp curve analysis 10-9 Chapter 11 - Maintenance Introduction 11-1 Replacing the sample tubing 11-1 Replacing fuses 11-2 Cleaning the covers 11-3 Cleaning the optics 11-4 Cleaning the cell windows 11-4 Cleaning the range lenses 11-6 Cleaning the beam expander 11-7 Appendix A - Specification Introduction A-1 G E T T I N G S T A R T E D Page v

8 CONTENTS G e t t i n g S t a r t e d Particle sizing specification A-1 Optical unit specification A-2 Computer requirements (minimum) A-4 Mastersizer programme specification A-5 Software Revision Level A-6 Appendix B - Chemical compatibility Introduction B-1 Components in contact with sample and dispersant B-1 Wet sample measurements B-1 Dry sample measurements B-1 Spray measurements B-2 Appendix C - Remote interlock Remote interlock C-1 Appendix D - Estimating the absorption Introduction D-1 Estimating the absorption using concentration measurements D-1 Appendix E - Advice for continuous sprays Introduction E-1 Arrange for the spray to be extracted E-1 Use the correct optical configuration E-1 Positioning the spray nozzle E-1 Don t spray the optical unit E-2 Ensure the spray is stable during measurement E-2 Page vi M A N

9 CONTENTS Appendix F - Malvern addresses Malvern subsidiaries F-1 Appendix G - EMC performance Statement of EMC performance G-1 Statement of EMC performance for the Mastersizer S G-1 Equipment under test G-1 Test conditions G-1 EMC performance G-2 Statement of EMC performance for the Mastersizer X G-3 Equipment under test G-3 Test conditions G-3 EMC performance G-3 G E T T I N G S T A R T E D Page vii

10 CONTENTS G e t t i n g S t a r t e d Page viii M A N

11 Introduction to this manual C H A P T E R 1

12

13 CHAPTER 1 Welcome Welcome to the Malvern Mastersizer Getting started manual. By now you should have installed your system by following the instructions in the installation manual. This manual is designed to give a brief overview of what the Mastersizer can do and how to do it. Obviously, all the features of the Malvern Mastersizer can not be given within this manual. More detailed information is given in other manuals, such as the Software Reference manual. After reading this Getting Started manual you will be able to; identify the main features of the system, understand the basic measurement technique, perform a simple measurement and analyse the data. If you have never operated a Malvern Mastersizer before it is recommended that you read this manual fully before you start your first measurement. Warning The Mastersizer or the samples to be measured may be dangerous if misused. You must read the Health and safety booklet before operating the system. Systems covered by this manual Mastersizer is a generic name given to a family of systems. Each system within the family uses the same principles of operation and only vary in operation in small areas. For this reason this manual has been written to cover more than one instrument. This manual covers the operation of the long and standard bench versions of the Mastersizer X and the Mastersizer S i.e. Instrument. Ref. Number. Mastersizer X standard bench. MAM 5000 Mastersizer X long bench. MAM 5002 Mastersizer S standard bench. MAM 5004 Mastersizer S long bench. MAM 5005 G E T T I N G S T A R T E D Page 1.1

14 CHAPTER 1 G e t t i n g S t a r t e d Access to the instrument Within this manual reference is made to the various people that will have access to the instrument. Below is a list of these people and their responsibility: Malvern personnel Malvern personnel (service engineers, representatives etc.) have full access to the instrument and are authorized to perform all service procedures that may require the removal of the transmitter and receiver covers. Supervisor The supervisor is the person responsible for the management/safety of the instrument and of its operation. The supervisor is responsible for the training of the operators. The supervisor can perform all user maintenance routines identified in chapter 11, including changing the fuses. The supervisor must on no circumstances remove the covers of the transmitter or receiver and should only remove the sample area cover when using the Mastersizer for spray measurements. Operator An operator is a person trained in the use of the instrument. The operator can perform all user maintenance routines identified in chapter 11 except for changing the fuses. The operator must on no circumstances remove the covers of the transmitter or receiver and should only remove the sample area cover when using the Mastersizer for spray measurements. Warning Failure to follow these guidelines could result in the emission of laser radiation. Laser radiation can be harmful to the body and can cause permanent eye damage. Page 1.2 MAN 0101

15 CHAPTER 1 Assumed information For clarity this manual will assume that you have a standard bench Mastersizer S. If there are any operational procedures that differ for the long bench Mastersizer S or the Mastersizer X then alternative information will be given. Most samples measured on the Mastersizer are those dispersed in a liquid. For this reason all references to a sample preparation accessory within this manual will refer to the Automated Sample Dispersion Unit. If you are using any other accessory then consult its manual for details of operation, installation etc. Within this manual it will be assumed that the flow cell is to be used. Again, if this is not the case for your particular installation consult the accessory manuals for details on installation and use of the cell you do have. Within this manual the Mastersizer system will be referred to as the Mastersizer or the system unless the information given is for a particular instrument. Windows terms It is important that you understand some Windows terms before reading further. (Note that US spelling is used for some terms for compatibility) Program - The Mastersizer software - it can also mean the Mastersizer Basic program used within the main Mastersizer software. Cursor or Pointer - The graphic - usually a pointer that is moved on the screen by operation of the mouse. Icon - The graphic on the desktop that represents a program. Click - The mouse button is depressed and released. If this is not qualified with a button description then assume it is the left button. Clicking a button means click the left mouse button when the cursor is over the button. Double-click - Press and release the mouse button twice in quick succession. If this is not qualified with a button description then assume it is the left button. Use the Mouse icon in the Control Panel of Program Manager to change the double-click speed. Dialogue Box - A window containing controls.theok button accepts changes in the dialogue box. The Cancel button closes the dialogue without accepting the changes. Control - This can mean a graphic on a dialogue like a button, listbox, textbox etc. G E T T I N G S T A R T E D Page 1.3

16 CHAPTER 1 G e t t i n g S t a r t e d Press or Select - This means click the mouse over a control or use the accelerator key (the underlined letter) or use the Tab key to move the focus to a control then use the Enter key. Menu items can be selected using the cursor keys in the same way. Button - This acts like a real-life button. Click to carry out an action. A typical button is shown below. Option Button or Radio Button - A series of buttons in a group, selecting one button cancels the others in the group. A radio button is shown below. Check Box - A button that can be toggled on and off. A check box is show below. Text Box or Edit Box - A box you can type text or values into. A text box is shown below. List Box - A box containing a list of options. Some List Boxes allow multiple entries to be selected. ILL 1996 ILL 1995 ILL 1994 ILL 1993 ILL 1992 Combination List Box or Combo Box - A combination of a list box with a text box. A button beside the text box displays or hides the list part of the control. In some cases you can type new values into the text box part, in others the text box just shows the current selection from the list. ILL 1997 Drag - An action with the mouse which involves moving the mouse while holding down the left mouse button. This is used for moving icons or making multiple selections in a list box. Page 1.4 MAN 0101

17 CHAPTER 1 Menu commands Menu commands from the Malvern software are referred to in the form main menu-menu item. As an example, the command File-Save Sample refers to selecting the Save Sample item in the File menu. The same rules apply for sub-menus of sub-menus, so that Edit-Copy-Data refers to the Data item in the Copy sub-menu, which itself is a sub-menu of the Edit menu. Menu commands are always shown in bold text. Where to find information As stated above this manual is designed to give a brief overview of what the Mastersizer can do and how to do it. In other words it is a quick guide that allows you to understand how the Mastersizer gets a result and runs you through a simple measurement procedure, hopefully steering you around the main pitfalls and directing you to more information if needed. If you have used a Malvern particle analyser before you may wish to go straight to chapters 4 and 5 where you can find practical information on making a measurement and analysing the data. However, it is recommended that you read this manual fully before you start a measurement. On-line help can be gained at any point when using the Malvern software. See chapter 2 for more details. The following is a list of the contents and objectives of the chapters within this manual. Chapter 2 - Features of the Mastersizer system. This chapter is designed to enable you to identify the physical features of the system and is divided into two parts. The first part identifies the features of the optical unit, for example the function of the connectors on the end panels or the purpose of the lenses etc. The second section does the same for the Malvern software, identifying the key areas of the screen. Chapter 3 - How the Mastersizer works. After reading chapter 3 you will have a basic idea of the operating procedures of the Mastersizer and in particular be able to: Know the basic operating principles. Know the simple steps involved in making a measurement and analysing the data. G E T T I N G S T A R T E D Page 1.5

18 CHAPTER 1 G e t t i n g S t a r t e d Chapter 4 - Making a measurement. Chapter 4 will guide you through the practical steps needed to make a measurement to obtain the raw data. Chapter 5 - Analysing the measurement data. This chapter will show you how to take the raw measurement data and analyse it, using the Malvern software, to get a final result. Advice is given on the choice of optical model and the presentation. Chapter 6 - Viewing the results. The Mastersizer software has several standard viewing formats that allow you to display and print the results in different ways. This chapter explains the standard views and how to print them. Chapter 7 - Interpreting the results. This chapter gives some essential advice on understanding the results given by the software. Chapter 8 - Automating the procedure. This chapter gives a brief overview of the procedures involved in measuring and analysing a sample by setting up a semi-automatic sequence. Chapter 9 - Sample preparation. Sample preparation is one of the most important stages in making a measurement on the Mastersizer. This chapter gives additional advice to that covered in the chapter 4. Chapter 10 - Advanced result processing. The Mastersizer software gives the option to perform some advanced result manipulation. This chapter gives an overview on some of the options. Chapter 11 - Routine maintenance. The Mastersizer has no user serviceable parts but there are certain maintenance routines that can be carried out by the user. These include cleaning the optics etc. This chapter gives advice on these routines. Appendices. At the rear of the manual is a series of appendices that cover some of the technical aspects of the Mastersizer, including the technical specification. Page 1.6 MAN 0101

19 CHAPTER 1 Other reading More detail on the subjects within this manual can be found in the following manuals: Title Ref. number The Malvern Software reference manual. MAN 0102 The Malvern BASIC reference manual. MAN 0103 Health and safety. MAN 0104 G E T T I N G S T A R T E D Page 1.7

20 CHAPTER 1 G e t t i n g S t a r t e d Page 1.8 MAN 0101

21 Getting to know your system C H A P T E R 2

22

23 CHAPTER 2 Introduction By now you should have connected up the system by following the instructions within the system and accessory installation guides. Spend some time to familiarise yourself with all the physical features of the system by reading the following sections. It is probable that you will not use all of the features described as some are used for specific accessories or applications only. This chapter is only intended to give you a guide to identify the features. A description of how the system actually works and how to use it will follow in the next few chapters. This chapter is divided into three sections. Section one will identify the main modules of a typical system. Section two will examine the features of the optical unit in more detail. Finally the third section will identify the main features of the Malvern software in more detail. Information on the sample preparation accessories can be found in their own manuals. A typical system The diagram below shows a typical system with its key features of the optical unit, one or more sample preparation accessories and a computer system. 3 1 I N S T R U M E N T S 2 ILL 1805 The optical unit is used to collect the raw data that is used to measure the size of a sample. The sole purpose of the sample preparation accessory is to prepare the sample and then deliver it to the optical unit so that it can be measured. Malvern makes G E T T I N G S T A R T E D Page 2.1

24 CHAPTER 2 G e t t i n g S t a r t e d many sample preparation accessories to handle all forms of sample, including dry powders, aerosols and samples dispersed in a liquid. You may have many sample handling accessories or none at all depending on your particular requirements. Consult the individual accessory manuals to identify the features of the sample preparation accessories. The computer system is a stand alone computer that runs the Malvern software. It is the Malvern software that analyses the raw data from the optical unit to give the size of the particles. Once completed the result can be further analysed or reports printed etc. The following section gives a more detailed overview of the features of the optical unit. The optical unit The optical unit consists of three components; the transmitter, the receiver and the sample area. Each of these components are identified in the diagram below. The purpose of the optical unit is to collect the information from the scattered light when a laser is passed through the sample to be measured ILL 3208 The transmitter The transmitter contains the laser and electronics that produces the laser beam that is used in the measurement of the sample. The main features of the transmitter are on the transmitter end panel. Use the figure below to identify these features and their function. Page 2.2 M A N

25 CHAPTER 2 5A FUSE 100V~ 260V~ pec Marking The Way ILL 3209 LV out connector Connector that carries the low voltage power supply to the receiver. Power input socket Main power input socket to the optical unit. Fuse holder Fuse for the optical unit. Read the health and safety manual before attempting to change the fuse. Interlock connector Laser interlock connector that shuts off the laser if any of the optical unit safety interlocks are defeated. This connector must be connected to allow the system to work. Remote connector Connection for an external laser interlock that turns the laser off when the interlock is defeated. The usual form of this interlock is a switch on the door to the room in which the system is installed that switches the laser off if the door is opened. See appendix C for details. If a remote interlock is not used then a shorting plug is connected to allow the laser to be powered. The system will not work without a shorting plug or a remote interlock connection. G E T T I N G S T A R T E D Page 2.3

26 CHAPTER 2 G e t t i n g S t a r t e d Laser power key The laser has to be turned on by turning the laser power key. This is an additional safety feature, allowing the key to be removed to stop unauthorised use of the system. Laser power indicator A visual indicator to warn the operator that the laser has been powered up by turning the laser power key. Optical unit power switch The main on/off power switch for the optical unit. The QSpec logo If your company operates within the pharmaceutical industry, you will be pleased to know that the Qspec sticker means that the instrument is eligible for coverage by a Malvern QSpec Validation contract which can help you to meet the requirements of the Food and Drug Administration (FDA). For further details contact your local Malvern Distributor. The sample area The area between the transmitter and receiver is the sample area. This is where the sample to be measured is passed through the laser. Use the diagram below to identify the main features of the sample area ILL 3210 Page 2.4 M A N

27 CHAPTER 2 Sample area cover Protective cover over the sample area. Designed to protect the operator from laser radiation and to keep the amount of background light to a minimum during a measurement. Warning! The sample area coremoved for spray measurements. Read the safety manual before removing the sample area cover. Unless you are performing spray measurements do not attempt to remove the sample area cover. Beam expander The beam expander is used to increase the diameter of the laser beam. Once the laser beam has been expanded it is known as the analyser beam. Note. The beam expander is actually part of the transmitter optics but has been included here for clarity. Range lens The purpose of the range lens is to collect the laser light that has been scattered from the sample and focus it onto the detector electronics. Both the Mastersizer X and Mastersizer S have a number of range lenses available, with each lens covering a different size range of particles. A list of lenses available and their corresponding size range is given below. Mastersizer X Mastersizer S Lens Size range Lens Size range 45mm µm 300RF µm 100mm µm 300mm µm 300mm µm 1000mm* µm 1000mm* µm * The 1000mm range lens are available on long bench versions only. G E T T I N G S T A R T E D Page 2.5

28 CHAPTER 2 G e t t i n g S t a r t e d Note. The range lens is actually part of the receiver assembly but has been included here for clarity. Caution! The optical unit will not operate correctly if more than one range lens is mounted at any one time. See Choosing a range lens in chapter 4. Sample cell The sample to be measured is passed through the analyser beam by propelling the sample through a cell. Malvern make various forms of cell to cope with different types of material. One exception to using a cell is the case of spray measurements where an aerosol is sprayed directly though the analyser beam. There are three types of cell available: Stirred cell. This is the simplest form of cell and is designed for samples dispersed in a liquid. The sample and its liquid dispersant are placed into the cell and the solution is kept in suspension by magnetically rotating a stirrer bead within the cell. Flow cell. A flow cell is also used for samples dispersed in a liquid. The sample and dispersant are kept in suspension by an external accessory that then pumps the solution through the flow cell. Air cell. An air cell is used when measuring dry powders. The sample is blown or dropped through the air cell by an external accessory. Cell pipe connectors If a flow cell is used then the connecting pipes from the cell to the sample preparation accessory are passed through the covers via the pipe connectors. Removable accessory panels Certain accessories, e.g. the Free Fall Dry Powder Feeder or the air cells, protrude outside the sample area cover. To facilitate this there are three removable accessory panels where one or more are removed to fit the accessory. Page 2.6 M A N

29 CHAPTER 2 Warning! Always replace the accessory panels after the accessory has been removed. Never run the system with the panels and accessory removed. Back scatter connector Mastersizer S only. The 300RF range lens has a back scatter detector which is connected to the back scatter connector on the receiver bulkhead. No other lens uses the back scatter connector. Laser interlock connector On the rear of the sample area cover is the laser interlock connector. This connection must be made if the laser is to work. The long bench versions of the Mastersizer have two interlock connections - one on the rear of each sample area cover. The receiver The final part of the optical unit is the receiver unit. The receiver collects and stores the information received from the scattering of the analyser beam as it passes through the sample. Once the data has been collected it is sent to the computer system for analysis. The main component of the receiver is the detector (sometimes called the diode). The detector is actually made up of a number of photo-diode elements that are arranged in a radial pattern. The detector is not visible in normal use. G E T T I N G S T A R T E D Page 2.7

30 CHAPTER 2 G e t t i n g S t a r t e d Caution: The detector is the most delicate (and expensive) component of the system. In normal use the detector is safely contained within the covers of the receiver unit. However, the Mastersizer X moves the detector within the covers. If the diode was in the position required for the 45mm range lens then the detector can be touched if the range lens was removed. On no circumstances touch or clean the detector. The main features of the receiver unit are on the receiver end panel. Use the figure below to identify the features on the receiver end panel and their function ILL 1808 Computer Comms connector Communication cable that is connected to the computer. Data from the receiver and control commands from the computer are transmitted down this cable. Page 2.8 M A N

31 CHAPTER 2 Aux. Comms connector Auxiliary communications connector. Some sample preparation accessories (e.g. Automated Sample Dispersion unit) are capable of controlling the optical unit. When this is the case they are connected to this connector. L.V. In connector Connector that carries the low voltage power supply into the receiver. Features to are usually used when performing spray measurements. Digital I/O connector The digital I/O connector is a general purpose user programmable I/O port. A particular use for the port is to connect the spray synchroniser accessory. Sweep trigger connector The sweep trigger is used to start a measurement sweep when using the spray accessories. Exp. trigger connector The Exp. trigger is the experiment trigger. The experiment trigger is used to start an experiment when using the spray accessories. Abort connector The abort connector is used to stop the experiment triggered using the Exp. trigger above. Differences between the long and standard bench Mastersizers The long bench Mastersizer is able to measure a larger range of particle sizes. To do this the long bench version has an extra sample area cover and an extra lens (the 1000mm lens). When the 1000mm lens is used it is mounted in the additional sample area. All other functions and features are the same as the standard bench. The following section gives an overview of the Malvern software. G E T T I N G S T A R T E D Page 2.9

32 CHAPTER 2 G e t t i n g S t a r t e d The Malvern software The Malvern software controls all the functions of the optical unit during a measurement and then uses the data collected to calculate the result. The software is Windows based, requiring version 3.1 or greater and has been designed to follow the guidelines laid down by Microsoft regarding the way in which the software is operated and how it co-operates with other Windows programs. Remember that, although the software is often operated using the mouse, all of the measurement functions are accessible by using the keyboard alone. If you are unfamiliar with using the Microsoft Windows environment you should read the Microsoft Windows manual. Running the Microsoft Windows tutorial will allow you to practice your mouse skills. The Mastersizer program group When the Mastersizer software is installed the Mastersizer program group shown below will appear in the Program Manager window. ILL 1867 There are three program icons within the program group. The first is the main Mastersizer program icon. To enable the Mastersizer software, double click on this icon. The second icon is the presentation generator program. This is a program that is usually run from the Mastersizer software but can be run independently by double clicking this icon. The presentation generator calculates new presentations that are used in the analysis of the measurement data. Presentations are discussed in detail later in this manual. The final icon is the Bitmap Editor. This program allows you to create your own icon bitmaps. Page 2.10 M A N

33 CHAPTER 2 Finding your way around the screen Before we explain how the software works you should familiarise yourself with some of the key features of the screen by using the diagram below ILL 1812 The main features are: Title bar (or Caption) This shows the name of the program (Malvern Mastersizer) and, among other things, tells you the name of the current sample file. Menu bar The menu bar contains the main menu headings for all Mastersizer functions. There are several ways to select an item from the menu bar: Using the mouse. To select an item from the menu bar use the left mouse button to click once on the menu item. The menu list will drop down. You can then select the item from the menu list by clicking once on the item. Using the keyboard. To select an item from the menu bar using the keyboard, hold down the G E T T I N G S T A R T E D Page 2.11

34 CHAPTER 2 G e t t i n g S t a r t e d Alt key and press the letter which is underlined in the item required. For example to use the Measure menu hold down Alt and press m. Whenever you use a key in this way it does not matter if you use upper or lower case. M or m would both work. Again a menu list will drop down. To select an item from the list type the letter that is underlined. For example, typing d will select the Document... item to enter sample details. Using keyboard accelerators. To the right of a menu item name there may also be a note of the accelerator for this item. This is a key or combination of keys which can be used to by-pass the menus. For example you can press Ctrl and N together to select Measure-Document... without having to use the main menu and drop down menu. The items which end with a row of dots (...) will cause dialogue boxes to appear. Those with no dots will cause an immediate action. For example Document... displays a dialogue for you to enter details but Clean would cause the sample handling unit to begin a cleaning sequence without any further action. Some items are shown in grey. This indicates that the choice is not currently available. For example, the Clean item may be grey because no sample handling unit is installed and the Background, Inspect and Sample items may be grey because these operations may not be performed until the system has been aligned. Calculate Button Setup Button Button Bar The Easy button bar (or toolbar) contains a selection of buttons which you can use to perform the most popular operations. Each button will have its equivalent commands within the menu bar. For example using the calculate button is equivalent to using the Calculate result... menu item from the Measure menu. A button may represent more than one command, for example pressing the setup button will automatically run you through the three Setup menu items; Setup-Hardware, Setup-Analysis and Setup-Presentation. The default button bar set when the Mastersizer software is first installed is: Page 2.12 M A N

35 CHAPTER 2 A B C D E F G H I J K L M N O ILL 1810 A - Setup B - Open Sample File C - Document D - Align Optics E - Measure Background F - Inspect Result G - Calculate Result H - Save Record I - Print J - Setup Sequence K - Start Sequence L - Clear Graph M - Graph Scale Up N - Graph Scale Down O - Exit Mastersizer To help you identify a menu button a short description of the action of the button is displayed in the status bar when the cursor is moved over the buttons - (The cursor also changes to a picture of a hand when over a button). As with the menu bar, if a button is not available it will be shown in a lighter colour to show it is disabled. i.e.: 1 ILL 1811 The keyboard can be used to select Easy buttons by using the key combinations which appears underneath each button. Because space is limited some of the text has been abbreviated, for example A+S+1 means hold down the Alt and Shift key while typing 1. It is possible to customise the button menu to suit your own needs. See Control-Easy Buttons in the software reference manual to change the layout of the buttons and the pictures that are used. You can also hide the key description which appears below the buttons. G E T T I N G S T A R T E D Page 2.13

36 CHAPTER 2 G e t t i n g S t a r t e d Table pane The table pane is used to show the result information in tabular form. Other information relevant to the measurement will also be shown. The type of information displayed in the table pane is determined by the view. The software has a list of standard views that can be easily changed by the user. Custom views can be created by the advanced user. To select a view, either select the View menu item or move the mouse cursor to any part of the table pane and press the right mouse button. This action will display a pop-up menu which shows you the selection of views available. Once selected the table and graph pages will immediately update. See chapter 6 for details of the views available. Double-clicking the left mouse button in the table pane has the effect of temporarily expanding that page to fill the window. Double-click again to restore the split screen. Scroll bars appear on the table pane if the pane is too small to show the whole table. Query Cursor Graph pane When a different view is selected the graph pane automatically changes to represent the data in the table. The graph pane always shows the same result but there are options to change the way it is displayed, for example the graph can be shown as a histogram, oversize plot, undersize plot, frequency plot or the result can be over-plotted on a graph of previous measurements. The form of each graph may be modified by clicking the right mouse button over the graph pane (or by selecting the Setup-Graph menu item). This produces a dialogue that allows plot styles, axes and colours to be changed. See Setup-Graph in the software reference manual for more information. If the left mouse button is pressed with the cursor over a graph the query cursor appears. Moving the query cursor over the graph displays information about the graph at the co-ordinates of the cursor. A typical message would be: x = 2.84 µm, y = 11.8% (59.1%). This means at this point of the graph that 59.1% of the sample is below 2.84 microns and that 11.8% of the sample is in that particular size band. Double-clicking the left mouse button in the graph pane has the effect of temporarily expanding that pane to fill the window. Double-click again to restore the split screen. The graph will automatically fit the graph pane. Page 2.14 M A N

37 CHAPTER 2 Splitter Bar Cursor Splitter bar The splitter bar allows you to change the proportions of graph and table panes i.e. to make the graph or table pane bigger or smaller. To move the split between graph and table panes using the mouse, move the cursor onto the splitter bar - the arrow cursor will change to a double-headed arrow. Now, hold down the left mouse button and drag the bar to the new position. Release the mouse button when the desired position is reached. The splitter bar may also be controlled from the keyboard or from the menus. Status bar The status bar is split into two parts. The left hand section is used to show the status of the software. It usually shows the message Ready - Press F1 for Help. This will change to inform you when the system is loading or saving files, calculating, etc. As a menu is selected or the cursor moves over a toolbar button help information is shown. The right hand part of the status bar shows the instrument status. The instrument status bar shows Instrument Ready if the optical unit is correctly connected and switched on and Instrument NOT READY otherwise. The instrument status bar will also show the progress of a measurement. Modes of operation The Malvern software has three main modes of operation, Easy, Menu and program mode, which are summarised below. Menu mode Menu mode is the use of the menu bar and its options to control the Mastersizer. Using the menus gives you access to all functions of the software. For full details of all the options in menus see the software reference manual. Easy mode The Easy button bar (or Toolbar) provides a simple way to select frequently used actions. For most samples a full analysis of a sample can be made by using the buttons. The buttons can be used by relatively inexperienced operators. G E T T I N G S T A R T E D Page 2.15

38 CHAPTER 2 G e t t i n g S t a r t e d Program mode The program mode uses the built-in program language Malvern Basic to allow you to build complex measurement sequences with prompts to enter values, perform actions, etc. and detailed checking of error conditions. Such programs may be run individually, assigned to single key operations or set up to run automatically when the software starts. The Malvern basic language is an advanced feature that is usually used by the more experienced user. The full details of programming in the Malvern Basic language are given in the Malvern Basic manual. The three modes above are designed so they can be used in conjunction with each other. You may find that you only need to use the easy mode buttons or just the menu items but it is possible to use all modes in a single measurement. For example you may align the system by pressing the align button from the button bar, but then follow by measuring the background by using the menu item Measure-Background. Always remember, as with most modern Windows programs, there is usually more that one way to operate the software. A function like printing a report for example can be done in several ways; by using the print option in the File menu, pressing the print button in the button bar or using the keyboard by pressing F11. Once you have gained experience in the operation of the Mastersizer it will be normal for you to set up automatic sequences of measurements that will automatically go from one procedure to the next, pausing only for you to enter details. To do this you set up a measurement sequence. The software also allows manual control of each stage. Even in manual control the system will take you from one stage to the next logical stage using a single key action. The system also locks-out actions that may lead to invalid measurements and gives warnings if measurements are not within accepted limits. Getting help On-line help Microsoft Windows contains a help program which can give information on using Windows itself and on programs that use Windows. As well as leafing through the manuals to find out how to do something you can also refer to the on-line Help Page 2.16 M A N

39 CHAPTER 2 system. Almost all the software reference manual is available on the Help system and in some cases is easier to search than the manual. Help Cursor The F1 Function key You can get help on using the Mastersizer software at any point by pressing the F1 function key. If the main Mastersizer window is active then the Help Contents page will be shown. If a dialogue box or other Mastersizer window is active then help on using that window will appear. This ability to give help on the operation being carried out is known as context-sensitive help. To get help on the main Mastersizer window hold down the Shift key and press F1. The mouse cursor then changes from the normal arrow to the Help cursor. When the Help cursor is active clicking the left mouse button over a component of the Mastersizer window will show help on that component. If a menu is selected or a button in the toolbar is clicked then help will appear on that command. The Help menu The far right menu in the Mastersizer menu bar is for Help. This allows you to go direct to specific parts of the Help system. The Help menu items are: Contents - The main list of contents in the Help system. Menu Command - The list of menu commands. Program Language - The contents of the help on using the built-in Mastersizer Basic language (program mode). Keyboard - How to use the keyboard for; commands, moving the splitter bar of the window and changing the scale the graph etc. Window - The list of Mastersizer window components. Help - This command displays the Microsoft Help information on using the Help system. For more information on the commands in the Help menu see the software reference manual. The Help window The Help window is an independent window with its own menu and sizing border. If you have the Mastersizer window maximised (filling the whole screen) G E T T I N G S T A R T E D Page 2.17

40 CHAPTER 2 G e t t i n g S t a r t e d you may find it useful to make the help window always stay on top of the Mastersizer window. To set the Help window to be always on top: Select the Help menu item from the Help window. If the Always on Top item does not have a check mark against it then click this item (or press the Enter key with this item highlighted). The Help window has a row of buttons below the menu for the most used actions: Contents - Pressing this button send you to the main contents page. Search - Selecting this displays the search dialogue - Searching Help. To search for the required information: Type the first few letters of the item to search for in the text box. The list box scrolls to show the item. Double-click the item in the list or press Show Topics. The list box at the bottom of the dialogue shows one or more topics. Select the topic in the bottom list box. Double-click or press Go To. The help window changes to the topic. Back - Pressing this button moves you to the last help topic displayed. History - This button displays a window showing a list of help topics visited. Double-click an item to go back to that topic. << and >> - These are the browse buttons - click these to see related topics to the current one. Glossary - Shows a list of glossary items. Click these to see the descriptions. Jumps and Popups In the Help window you will see text which is underlined with a solid line for example Diffraction. Click this to move to another topic. This is known as a jump. Text that is underlined with a dotted line will show a popup window with extra information when it is clicked with the mouse. Click the mouse in the window to make it disappear. This is known as a popup. When the mouse cursor moves over a jump or popup item it changes to the help jump cursor. Page 2.18 M A N

41 CHAPTER 2 Help Jump Cursor The cursor also changes when it moves over certain graphics and buttons. Clicking these items show more information about them. Status line When a menu is selected or the mouse cursor moves over a toolbar button the status line at the bottom of the Mastersizer window will show information on the command. Reporting Problems Before reporting a problem please check the relevant sections of the user and reference manuals, or any accessory manuals, which may have an answer. If the problem persists try to give as much detail as possible. If there is a problem in the software try to give information that will allow the engineers at Malvern to reproduce the conditions. If the problem is in the result or the analysis the Malvern engineers will require a copy of the Data report. A list of the Malvern subsidiaries can be found in appendix F. To print a data report: Change the View to Data. Select a report print in the File - Print dialogue. G E T T I N G S T A R T E D Page 2.19

42 CHAPTER 2 G e t t i n g S t a r t e d Page 2.20 M A N

43 How the Mastersizer works C H A P T E R 3

44

45 CHAPTER 3 Introduction After reading this chapter you will have a basic idea of the operating procedures of the Mastersizer and in particular: Know the basic operating principles of the Mastersizer. Know the simple steps involved in making a measurement and analysing the data. More detail will be given in later chapters. What does the Mastersizer do? Scientists have for centuries tried to predict the way particles scatter and absorb light. There are many theories and models that the modern particle analyst can use. One of the simplest theories used is the Fraunhofer model. This model can predict the scattering pattern that is created when a solid, opaque disc of a known size is passed through a laser beam. This model is fine for a lot of particles but it does not describe the scattering exactly. Very few particles are disc shaped and a lot of particles are transparent. The Mie theory was developed to predict the way light is scattered by spherical particles and deals with the way light passes through, or is adsorbed by, the particle. This theory is more accurate but it does assume you know some specific information about your particle, such as its refractive index and its absorption. The key fact about these theories is that if you know the size of the particle and other details about its structure, you can accurately predict the way it will scatter light. Each size of particle will have its own characteristic scattering pattern, like a fingerprint that is unlike any other size of particle. So how does the Mastersizer measure the size of particles? The Mastersizer works backwards from the above theories by using the Mastersizers optical unit to capture the actual scattering pattern from a field of particles. Then using the theories above it can predict the size of particles that created that pattern. G E T T I N G S T A R T E D Page 3.1

46 CHAPTER 3 G e t t i n g S t a r t e d How does the Mastersizer do it? There are two distinct procedures involved in measuring a sample on the Mastersizer. Firstly there is the capturing of the scattering pattern from the sample - this is known as the measurement. This is the purpose of the optical unit. The detector within the optical unit is made up of many individual detectors. Each detector will collect the light scattering from a particular range of angles. A typical light scattering pattern is shown below Obscuration = 10.3 % Data Background Detector Number ILL 1857 Each bar in the histogram represents the light scattering from one of the detector elements. The detector takes a snap-shot of the scattering pattern. Obviously this snap-shot will only capture the scattering pattern from the particles that where passing through the analyser beam at that particular time. Taking only one snap-shot may not give you a representative reading of the scattering pattern. To overcome this the Mastersizer takes many snap-shots (known as sweeps) and averages the result. Typically over 2000 sweeps are made for each measurement, with each sweep taking 2mS. Secondly, once the measurement is complete the raw data contained in the measurement can be analysed by the Malvern software using one of the theories above. The measurement data is analysed by first selecting a presentation. A presentation is a predicted scattering pattern from theoretical particles. The software has many presentations on disc that represent particles of different materials suspended in different dispersants. You will choose the presentation that matches the sample and dispersant you are measuring. Page 3.2 M A N

47 CHAPTER 3 The presentation data is then made to fit the measurement data - this will give you the final size distribution. Once the data has been analysed the information can be displayed in various ways. Usually the display will show you a graph of the result and a table showing the same information in a tabular form. The graph below shows four of the more common graph types for displaying the result. 20 Volume % Particle Diameter (µ m.) 0 ILL 1869 The histogram displays the result in the form of in band percentages. i.e. each bar in the graph represents a size band of particles (52-59 microns for example) and the height of the bar represents the percentage of the sample that is within that band. The histogram graph uses the left scale. Unless you change the size bands, the initial analysis uses the size bands that are set by the physical design of the detector. The undersize plot displays the result in the form of % of sample below a certain size of particle. For example by reading the values from the graph you may be able to determine that 10% of the sample is under 23 microns etc. (the exact value can be read from the table that will accompany the graph). The undersize plot is read from the right hand scale on the graph. The undersize plot is calculated from the initial size bands by fitting a curve to the analysis data so that values within a size band may be read. The oversize plot is similar to the undersize plot except that the result is in the form % of sample above a certain size of particle. For example by reading the values from the graph you may be able to determine that 90% of the sample is above 23 microns etc. The frequency curve is calculated by differentiating the undersize curve. The frequency curve is particularly useful for displaying the results to show the G E T T I N G S T A R T E D Page 3.3

48 CHAPTER 3 G e t t i n g S t a r t e d modes or peaks in the graph. Several peaks in the graph indicate that there are distinct sizes of particles within the sample. This at a glance inspection of the results will be difficult if the result was shown as an undersize or oversize plot. Another use for the frequency curve is to compare results from different measurements - over-plotting results can be done using other graph types but the graph may become confusing. It is usual for the operator to use the software to setup a sequence that will automatically go through the procedures above in one go. There is a large choice of options when setting up a sequence, for example, you can easily arrange for the Mastersizer to measure a single sample many times, each time analysing the measurement data (using a pre-chosen presentation), saving the result and over-plotting each result on a graph. Alternatively you can go through each stage individually. Before you setup a sequence it is important to understand the procedures in each stage. The following section explains these procedures How to make a measurement It is vitally important that the measurement is carried out correctly. It should be obvious that if you make a poor measurement then no amount of analyzing of the data can give you a good result. A brief note on each stage of the measurement follows. The practical procedures for making the measurement is covered in chapter 4. Setup for the measurement The Malvern software will need to know some of the physical parameters of the system, i.e. which lens is fitted or the type of sample preparation accessory is attached. Obviously this will only be done once and will only have to change if you alter the physical setup, by changing a lens for example. Align the optics If the instrument has just been switched on or any of the optics have been moved (removing and cleaning the cell for example) you will have to align the laser so that it hits the centre of the detector. This is a totally automatic procedure with the Mastersizer and only requires the pressing of a single button. Page 3.4 M A N

49 CHAPTER 3 Document the measurement It is always good practice to document your measurement so that you will be able to identify what was measured and how it was measured. A short sample identifier and notes can be saved with the measurement. Measure the background The scattering pattern from your sample is contaminated by light scattered by impurities within the dispersant, on the windows and lenses and also electrical noise. To remove this contamination a background measurement is made that measures the scattering pattern with no sample in the analyser beam. This background measurement is then subtracted from the scattering pattern with the sample present to leave only the information from the particles. Add the sample and inspect the concentration The correct amount of sample has to be passed through the laser beam to allow a good measurement to take place. Too little sample and there will not be enough scattered light to be detected. Too much sample and the light scattered from an individual particle will itself be scattered by other particles - this is known as multiple scattering. The Mastersizer determines the correct concentration of the sample by measuring the amount of laser light that has been lost by passing it through the sample. This is known as the obscuration and is given as a percentage. For example if 30% of the laser light is lost when it passes through the sample it is said to have an obscuration of 30%. Sample is added to the system until the obscuration is within an acceptable range. Note. The preparation of the sample before it is added to the system can be critical. Over half of the problems encountered when measuring a sample are caused by bad sample preparation. If your sample is sticking together, dissolving, floating on the surface or if you have failed to get a representative sample you will not get a correct result. Read chapter 9 for details on sample preparation. Measure the sample Once all the steps above are completed the scattering pattern is then measured. G E T T I N G S T A R T E D Page 3.5

50 CHAPTER 3 G e t t i n g S t a r t e d It is usual at this point to go on and analyse the measurement but it can be saved on the computer so that it can be analysed at a later date if you wish. How to analyse the measurement data There are three steps required to analyse the measurement data: Choose the analysis model to be used. Choose the presentation to be used. Tell the computer to calculate the result. The analysis model The analysis model tells the computer what the expected shape of the result graph will be. There are four choices available; polydisperse, multimodal, monomodal or very polydisperse. Polydisperse model does not assume anything about the shape of the result graph. Multimodal model assumes that there will be one or more distinct peaks in the results graph - indicating that there are several distinct sizes of particles. The monomodal model assumes that there will only be one peak in the result graph - indicating that there is only one size of particle. Very polydisperse is similar to polydisperse but is only used for one or two special circumstances. (For Mastersizer X only.) See chapter 5 for more information. Compressed range analysis has a reduced upper size limit and is meant for use with dry powder and spray measurements. (For Mastersizer S only.) The choice of which model to use is very simple - unless you definitely know that the result graph will be of a particular shape always use the polydisperse model. The presentation As stated earlier, the Mie theory needs to know specific information about the structure of the sample and the medium it is suspended in so that it can calculate exactly how light passes through them. The specific information required is the relative refractive index of the particle to be measured, the particle adsorption Page 3.6 M A N

51 CHAPTER 3 (imaginary refractive index) and the refractive index of the medium that the particle is suspended in (dispersant). Once the Malvern software knows this information it can calculate the expected scattering pattern from these particles. This scattering pattern is known as the presentation. The presentation is identified by a label of the form 3OHD. The details of how these codes are made up will be discussed later. There are three ways of selecting a presentation. The easiest way is to use one of the four default or system presentations. These are; Fraunhofer (3$$D). This is the presentation that is used when you wish to use the simpler Fraunhofer model. Standard - Wet (3OHD). This is a presentation that takes a middle of the road value for the refractive index and adsorption of the sample and assumes that the particle is suspended in water. Standard - Dry (3RHA). This presentation is the same as standard-wet except assumes that the particle is suspended in air. Reference Reticle (3$$1). This is the presentation that is used when the Diffraction Reference Reticle accessory is used to validate the system. Obviously this will only be used if you have the accessory. Read the Diffraction Reference Reticle accessory manual for further details. For a more accurate choice you can enter the refractive index of the particle etc. and the software can then find the nearest match from the many precalculated presentations stored on the computer. Thirdly, if you require an exact presentation you can again enter the particle details and then ask the software to generate the exact presentation. You may ask yourself If I can generate the exact presentation why bother with a default or near-match choice. Firstly, generating the exact presentation takes time. Secondly, for most samples using either the standard-wet or standard-dry presentations are more than sufficient. Choosing another presentation is only required in specific circumstances, such as the majority of particles being under 10 microns in size. Details of choosing the correct presentation are given in chapter 5. Until you know more about choosing a presentation it is recommended that you use one of the two standard presentations. Calculating the result Once the analysis and presentation have been selected, the result is calculated by simply pressing the calculate button. The progress of the calculation of the result G E T T I N G S T A R T E D Page 3.7

52 CHAPTER 3 G e t t i n g S t a r t e d is shown on the screen by the Residual. The residual is an indication of how closely the calculated data has been fitted to the measurement data and is expressed as a percentage. By examining the residual you will be able to determine if the correct analysis mode or presentation has been chosen. Viewing the result Once the software has finished calculating the result, the graph pane and table pane of the screen are updated to show the new result, using the present settings for the displays. The result data can be shown in different forms by loading in a different view. There are several standard views available or you can create your own. Details of the views available are described in chapter 6. Saving the result It is important to have a structured way to save all of your data so that in can be locatedeasily in the future. There are three items you need to understand to successfully file your data. These are: Records. Run number. Sample file. A record contains all the data that has been collected for a particular experiment. A record will contain the measurement data, the analysis data, notes on the experiment and the run number. A record is identified by a sequential record number. If you run a number of experiments, on the same sample for example, the run number can identify the sequence of results. The run number can either increment after analysis or after saving. A sample file is a file that contains a collection of records. The sample file takes the form of a file name with a.sam extension. It is probably easier to understand these terms by following a practical example. Suppose you had to measure some samples from a production line that operated 5 days a week and 4 hours a day. Every hour you have to take 3 samples from the production line and measure these samples. One way to store these results is to have a separate sample file for each day of the week. A typical structure of the sample file for one day (Monday) is shown on the next page. Page 3.8 M A N

53 CHAPTER 3 Sample file: Monday.SAM Record Number Run Number As can be seen, the run number is reset after each batch of 3 samples. So, for example, to see the data for the second sample taken two hours into Monday, you will open record number 5 from the MONDAY.SAM sample file. G E T T I N G S T A R T E D Page 3.9

54 CHAPTER 3 G e t t i n g S t a r t e d Page 3.10 M A N

55 Making a measurement C H A P T E R 4

56

57 CHAPTER 4 Introduction It is usual for the operator to use the software to setup a sequence that, once set up, will automatically go through the procedures of measuring the sample, analysing the data and saving the results by simply pressing a single button. However, it is important to know the individual stages that are involved. This chapter is concerned with the measurement of the sample - the next chapter will give the practical details on analysing the data. In chapter 3 the section How to make a measurement gave a brief overview of the stages involved in making a measurement. These stages where: Setup the system. Document the sample. Align the optics. Measure the background. Add the sample. Measure the sample. This chapter will explain the practical steps of each of these stages. It has been found that the best way to learn how to measure a sample is to actually make a measurement on a system. To get the most benefit from this chapter it is advised to read through the chapter first and then to go through a second time following the instructions to make a measurement on the system. To do this you will need a suitable sample to measure and a suitable dispersant to disperse it in. Either ordinary dairy cream or a PVA glue dispersed in water are readily available samples and dispersant that should give you good predictable results. By the end of this chapter you will have gained the practical knowledge that is needed to perform a measurement, such as which range lens to choose or how to prepare the sample etc. This knowledge will allow you to understand the procedures involved in setting up a measurement sequence. General measurement advice Before we make a measurement there is some important general advice that should always be noted. G E T T I N G S T A R T E D Page 4.1

58 CHAPTER 4 G e t t i n g S t a r t e d Sample preparation Firstly the most important thing to consider is the preparation of your sample before it is measured. A representative sample must be taken. Dry powders, for example, tend to separate out if stored for some time or vibrated. The larger particles tend to rise to the top and the smaller particles collect at the bottom of the container. If you were to take the sample from the top of the container it will not contain the smaller particles, giving you a biased measurement. The sample should be correctly mixed before a measurement is taken. Wet samples have also to be correctly dispersed in a liquid dispersant. Using the wrong dispersant can cause the sample to stick together in lumps, float on the surface or even dissolve. The sample and dispersant should be checked to see if they are suitable before a measurement is made. There are many ways to prepare your sample to ensure a perfect measurement. Details on sample preparation are given in chapter 9. Note. It has been found that over half the problems encountered in measuring the sample have been caused by bad sample preparation. It should be obvious that if you make a bad measurement that no amount of analysing will give you a good result. Cleanliness of the optical system Laser scattering is a high resolution optical method in which the lenses and cell windows are an integral part of the measurement zone. Dust or smears on the lenses will scatter light that will be measured with the sample scattering. In general the process of measuring both a background and a sample and then subtracting the two corrects for such contributions. However this correction is first order only and excessive dirt on the optics degrades the instruments sensitivity. You are recommended to ensure at all times that your lenses and cell windows are clean. Use the procedures described in chapter 11 for advice on cleaning the system. If you are in doubt about the optical cleanliness then you can use the live display of scattered light to view the background measurement. By viewing this screen you will be able to judge if the optics are clean or not. This procedure is described in chapter 11. Page 4.2 M A N

59 CHAPTER 4 Choosing a range lens The Mastersizer has several range lenses available. For this initial measurement you will be using the 300RF lens on the Mastersizer S or the 45mm lens on the Mastersizer X. If you have followed the installation manual successfully then one of these lens will already be installed, if not go back to the installation manual and add the appropriate lens. In future though you will have to know which lens to choose. There are two main things to consider - the size range of your sample and the method of dispersing your sample. Size range of your sample The choice of lens will depend on the size of the particles within the sample. Each range lens covers a different size range of particles. The table below gives these ranges. Mastersizer X Mastersizer S Lens Size Range Lens Size Range 45mm µm 300RF µm 100mm µm 300mm µm 300mm µm 1000mm* µm 1000mm* µm NOTE Each lens can be identified by removing the front lens cap. The name of the lens is engraved on the lens ring. (* Used on the long bench Mastersizers only.) You will have to use a lens that covers the size range of particles in your sample. For example if you have a sample with particles in the range of 2 microns to 10 microns, using the 1000mm lens will not allow you to measure the bottom range of the sample. Using the 300RF lens though will give you the correct range. You may have noticed a problem with the above statement. How do you know the size range of the sample before you have measured it? If you do not know the size range of your sample you will have to perform a test measurement. If the range lens you are using is cutting off the results then the result has a characteristic look. The measurement below shows a sample measured on the µm range lens (300mm lens on the Mastersizer S). G E T T I N G S T A R T E D Page 4.3

60 CHAPTER 4 G e t t i n g S t a r t e d Particle Diameter (µm.) ILL 1870 The graph shows that the distribution is cut off at the large size end. Clearly there is a significant amount of material at sizes above 900µm. Not only is this material missed in the measurement but the light scattered by that material also distorts the measurement of the material which is in the range. For such a material, the µm range (1000mm lens on the Mastersizer S) would be more suitable as shown in the second graph below Particle Diameter (µm.) ILL 1871 Page 4.4 M A N

61 CHAPTER 4 Sample dispersion method The second thing to consider when choosing a lens is the way the sample is dispersed. Because of the physical arrangement of the 45mm and 300RF lenses it is not possible to measure samples dispersed in air (i.e. using one of the dry powder feeder accessories or performing spray measurements) using these lenses. Due to lens cut off (discussed next) the 100mm lens on the Mastersizer X is also unlikely to be used for spray measurements. As general advice: Spray measurements should only be performed on the 300mm or 1000mm* lens. Samples dispersed in a liquid should initially be tried using the 45mm lens on the Mastersizer X or the 300RF lens on the Mastersizer S. If the size range of the sample is then found to be outside the ranges for these lenses then try another lens. Avoiding lens cut off (Vignetting) Care should be taken when measuring spray samples. It should be noted that there is a physical measurement zone - an area in front of the range lens that the spray must be confined to. If you spray outside this area then the scattering information will not be picked up by the detector. This measurement zone is defined by the cut off point, a distance from the face of the range lens along the analyser beam. The chart below gives the cut off point for the lenses. (The 45mm and 300RF lens have not been included as it is not possible to measure spray samples with these lenses). Mastersizer X Mastersizer S Lens Cut off. (mm) Lens Cut off. (mm) 100mm mm mm mm* mm* 290 (* Used on the long bench Mastersizers only.) G E T T I N G S T A R T E D Page 4.5

62 CHAPTER 4 G e t t i n g S t a r t e d The lens cut off point is only an issue when using the Mastersizer for spray measurements. Other forms of measurement use a cell to confine the samples within the measurement zone. Note. It should be noted that spray measurements can be made with the sample beyond the cut-off point but the outer detector elements must be removed from the analysis using Kill data. Always measure a background The background measurement is used to subtract the ambient light signals from the total scattering received from your sample. This allows the instrument to differentiate stray light from sample scattered light and is important for accurate results. The background should ideally be freshly taken for every sample that you analyse. It is advisable to measure the background as near as possible to the time at which your sample is to be measured, to avoid changes in ambient lighting conditions. Exceptions to this rule occur when you wish to run a series of measurements on the same sample. Here the one background measurement is applied to all the measurements. This is necessary to allow them to proceed without operator intervention. In such circumstances the user is advised to operate under stable lighting conditions if the sample area cover is removed from the instrument (i.e. when measuring sprays). Making a measurement We shall now go through the practical steps in making a measurement. Instrument preparation By now you should have connected the system by following the instructions in the installation manual and the dispersion unit manual (We are assuming that you are using Automated Sample Dispersion unit - if not consult the manual of the accessory that you do have). Check that: The computer, optical unit and dispersion unit are connected and switched on. For this measurement the 300RF lens (Mastersizer S) or the 45mm lens (Mastersizer X) is fitted and both lens caps are removed. The beam expander is fitted and the lens cap removed. Page 4.6 M A N

63 CHAPTER 4 The flow cell is fitted and the pipes are connected to the dispersion unit according to the instructions in the Automated Sample Dispersion Unit manual. Before you begin a measurement you will have to tell the computer about the physical features that you have just set up, i.e. which lens and sample accessory you are using. These details are entered by filling in the Setup Hardware dialogue. This only needs to be done once and will only have to change if you change a lens or an accessory. The computer will remember the setup if you save the configuration. You will be automatically asked if you wish to save the configuration when you exit the software. To setup the hardware: Select Hardware from the Setup menu. The dialogue below will appear. 1 2 ILL 2055 NOTE It is not essential for the operation of the system to change the name of the sample unit - it is recommended however as the name of the sample unit selected here is printed in the result reports. Change the range lens setting by clicking on the arrow and selecting 300RF for the Mastersizer S or 45mm for the Mastersizer X. Change the sample unit by clicking the arrow and selecting Auto Sample Dispersion Unit. If you do not have a Automated Sample Dispersion Unit then select the option for the accessory you do have. Select OK. Remember to save the configuration when prompted to do so when exiting the software! G E T T I N G S T A R T E D Page 4.7

64 CHAPTER 4 G e t t i n g S t a r t e d Document the measurement It is good practice to document the measurement so that you will be able to identify what you where measuring and how you measured it at a later date. The Malvern software has a document dialogue that allows you to enter a name for the sample and enter details that will allow you to recreate the measurement in the future - such as how much sample you added, what dispersant you used, the pump speed etc. NOTE To document the measurement: Select Document from the Measure menu. The document dialogue shown below will appear. An alternative to selecting Measure-Document is to press the document button. ILL 2056 Within the box labelled Sample name type in a name for the measurement. The name can be up to 20 characters. For this demonstration type Cream or PVA glue depending on the sample you have chosen. The Notes section can take up to 4 lines of text that describes your measurement. For example, type in Water dispersant. Using Automated Sample Dispersion Unit - pump speed 75% stirrer 50%, ultrasound 20% Select OK. An introduction to the measure windows The rest of the measurement procedures, align the system, measure a background, add the sample and measure the sample are controlled by the measure windows; measure-align, measure-background, measure-inspect and measure-sample. The four windows all look very similar and have common features. A typical window is shown below. Page 4.8 M A N

65 CHAPTER ILL 2057 The ease of use of the Malvern software is demonstrated with these windows. It is of course possible to perform each of these tasks individually by first selecting Align from the Measure menu, aligning the system, then closing down the align window and then opening the next window, etc. A far easier way is to use the Next button. Pressing the Next button will take you automatically to the next logical dialogue in the sequence. Continually pressing the Next button will take you through the complete measurement sequence. The Next button is one of four buttons in the measure window that allow easy control of the measurement sequence. A quick summary of these four buttons are shown below. Start. The Start button starts the measurement (either align, background, inspect or sample ). When the start button is selected it will change to say stop, allowing you to stop the task at any point. When the task is completed the button will change back to start. Close. The Close button will close down the current measure dialogue and return you to the main screen. Next. As described above, the Next button will take you to the next logical step in the measurement sequence. Previous. Pressing the Previous button will take you back to the previous measurement window. For example, if you pressed the Previous button while in the Measure-background window it will take you back to the Measure-Align window, allowing you to re-align the system if you require. Two other features of the Measure windows are the live display and the laser power bar. G E T T I N G S T A R T E D Page 4.9

66 CHAPTER 4 G e t t i n g S t a r t e d The live display shows the scattering pattern that is detected by the detector. As stated earlier, the detector is actually made up of series of photo diodes, arranged in a radial structure. The individual diodes are numbered, with the diode at the centre being numbered zero. The live display shows the scattering pattern from diode 1 outwards. NOTE An alternative to selecting Align-Measure from the menus is to select the align button. The laser power bar gives an indication of how well the system is aligned. The laser power bar gives a reading from the central detector (detector zero). The bar is colour coded to give a visual indication of the laser power, if the bar is green then the laser power is acceptable. If red then the laser power is too low. The laser power bar is linked to the laser power reading that shows the laser power as a percentage. The rest of this section will take you through the rest of the measurement sequence using the measure windows. NOTE Instead of manually doing an alignment you may chose to enable the Intelligent Align control in the Set Alarm Limits dialogue. This automatically performs an alignment before each background measurement if it senses that the alignment has degraded. A good alignment must still be performed manually at the start of the session or whenever a range lens is changed. Align the system The laser must be aligned centrally on the detector. An alignment must be made whenever any of the optics (the cell, range lens, beam expander etc) are removed or replaced. An alignment should also be made after the system has been first switched on and had time to stabilise its temperature. If an alignment has not been made the software will not allow you to go on to the other measurement dialogues by greying out the options. To align the Mastersizer: Select Align from the Measure menu. The dialogue below will appear. 1 ILL 2058 Select the Start button and the instrument will automatically align. The Start button will change to Stop. When the alignment is complete the button will change back to Start. Alignment usually only takes a few sec- Page 4.10 M A N

67 CHAPTER 4 onds to complete, but if the system is badly out of alignment it may take up to two minutes. When aligned the laser power reading should show a value greater than 75. Take a background measurement A background measurement is taken to measure the background electrical noise and the laser scattering from contaminants on the optics and within the dispersant. It is important that the cell is full of clean dispersant. If you have followed the installation instructions correctly the dispersion unit will already be pumping a dispersant around the cell at a pump speed of about 40%. If not follow the instructions within the Automated Sample Dispersion Unit to fill the unit with water and pump with the correct pump speed. NOTE If you are not in the Measure-align dialogue you can select the Measure-background dialogue by selecting Background from the Measure menu or alternatively you can select the background button. To take a background measurement: From the Measure-align dialogue press the Next button. The Measurebackground dialogue shown below will appear. ILL 2059 Press the Start button and the background measurement will automatically start. Messages will appear on the right hand status line to show the progress of the measurement. The Start button will change to Stop while the measurement takes place, allowing you to stop the measurement if you need to. When the button changes back to Start the measurement is complete. Add the sample The correct amount of sample has to be added to the system. G E T T I N G S T A R T E D Page 4.11

68 CHAPTER 4 G e t t i n g S t a r t e d The system measures whether the concentration is suitable by monitoring the obscuration of the beam caused by the sample being added to the dispersant. The obscuration is simply the fraction of light lost from the analyser beam when the sample is introduced. For example an obscuration of 30% means that 30% of the analyser beam (recorded during the background measurement step) has been lost to either scattering or absorption. The Measure-inspect dialogue will tell you the exact concentration of the sample within the dispersant and whether it is ideal, too low or high etc. The obscuration bar ( in the figure below) gives a visual indication of the concentration of the sample. If the bar is green then the concentration is in the correct range. If orange then it is approaching the correct range and if red then the concentration is out of range. The exact obscuration is given at the bottom left of the dialogue ( in the figure below). The instrument has a wide range of concentrations that are ideal and thus concentrations do not have to be precise. The range of concentrations over which the instrument can be used can be conveniently expressed in obscuration terms as below. Obscuration ranges Range % Bar colour Notes <5% Red Too low. Add more sample % Orange Low but usable with a good sample measurement to background measurement ratio. Add more sample if possible % Green Ideal % Orange There is a possibility of multiple scattering. Usable but try to add more dispersant. >50 % Red Too high. Before you add the sample to the system it is usually best to pre-disperse the sample within a little of the dispersant to form a slurry. To do this add a small amount of your sample (in this demonstration use either ordinary dairy cream or PVA glue) to a small beaker and add water. Use a pipette to thoroughly mix the sample. When you come to measure your own samples, other than cream or PVA glue, it will be of great benefit to read chapter 9 on sample preparation. To add the sample: From the Measure-background dialogue press the Next button. The Measure-inspect dialogue shown below will appear. Page 4.12 M A N

69 CHAPTER 4 NOTE If you are not in the Measure-background dialogue you can select the Measure-inspect dialogue by selecting Inspect from the Measure menu or alternatively you can select the Inspect button. 2 1 ILL 2066 Press the Start button and the instrument will start to measure the obscuration. The Start button will change to Stop while the measurement takes place, allowing you to stop the measurement if you need to. Using the pipette add the sample to the dispersion unit. Add a few drops at a time and allow the sample to be thoroughly mixed within the dispersant. Look at the obscuration bar. The objective is to add enough sample to turn the bar green (giving a value of between 10 and 30%) on the readout. Once you are satisfied that the sample concentration is in the correct range you can continue to the final stage of the measurement. Caution Do not spill any dispersant or sample onto the surfaces of the cover. It has been found that certain substances can cause permanent damage to the covers. All spillage should be scrupulously cleaned up immediately. Measure the sample The final stage of the measurement procedure is to measure the sample. To measure the sample: From the Measure-Inspect dialogue press the Next button. The dialogue below will appear. G E T T I N G S T A R T E D Page 4.13

70 CHAPTER 4 G e t t i n g S t a r t e d NOTE If you are not in the Measure-Inspect dialogue then you can select the Measure-Sample dialogue by selecting Sample from the Measure menu. ILL 2060 Press the Start button and the measurement will start. The Start button will change to Stop allowing you to stop the measurement if you require. Once the measurement is complete the button will change back to say Start. The measurement is now complete. The next procedure to follow is the analysis of the data you have just measured. This is described in the next chapter. At this point you have the option of saving your measurement data - for this demonstration though we will carry on with the analysis and save the result later. The dialogue at present will still show the Measure-Sample dialogue. It is possible to press the Next button that will take you to the next logical step in the procedure - analysis of the data. At this point it is not recommended as it will analyse the data using the parameters of the last sample analysed. It will be of more benefit to you to follow the procedure in the next chapter that will explain the setup of the analysis. To close down the Measure-Sample dialogue press the Close button. Page 4.14 M A N

71 Analysing the measurement data C H A P T E R 5

72

73 CHAPTER 5 Introduction This chapter describes the analysis of the measurement data. There are three steps involved; choosing the analysis mode, choosing a presentation and finally telling the software to calculate the result. It should be remembered that the measurement data is never changed during the analysis. This allows the operator to re-analyse the measurement data using different choices of analysis mode or presentation. Normally you would probably choose the analysis mode and presentation before you made the measurement so that when the measurement was complete you would only have to select the Next button to analyse the result. However for this demonstration it will give you a better understanding of the way the system operates by selecting the options now. Again you will gain most benefit if you were to analyse actual data on the system. It is recommended that you read through this chapter once then go through a second time following the instructions to analyse the data you measured in the previous chapter. By the end of this chapter you will gain the practical knowledge that is needed to choose the correct analysis mode and presentation. Choosing the correct analysis mode The analysis model tells the computer what the expected shape of the result graph will be. There are five choices available; polydisperse, multimodal, monomodal, very polydisperse, and compressed range. Polydisperse model does not assume anything about the shape of the result graph. Multimodal model assumes that there will be one or more distinct peaks in the results graph - indicating that there are several distinct sizes of particles. The monomodal model assumes that there will only be one peak in the result graph - indicating that there is only one size of particle. Very polydisperse is similar to polydisperse but is used for a few special circumstances. (Mastersizer X only). Compressed range analysis has a reduced upper size limit and is meant for use with dry powder and spray measurements. (For Mastersizer S only). G E T T I N G S T A R T E D Page 5.1

74 CHAPTER 5 G e t t i n g S t a r t e d The choice of which model to use is very simple - unless you definitely know that the result graph will be of a particular shape always use the polydisperse model. So, when will you use the other modes? The multimodal model assumes that there are a few distinct sizes of particles within the sample. For example your sample may be made up of predominantly 10 micron, 50 micron and 100 micron particles. You will use the multimodal model only if you are sure that your sample is made up of distinct sizes. The monomodal model is very similar to the multimodal model but will assume that there is only one size of particle in the sample. Typically this will be used for measuring standards such as latex samples that have been specially made to be of a known size. Again, only use this model if you definitely know that the sample is made of single sized particles. Very polydisperse is only used on the Mastersizer X and is a special purpose model that is similar to polydisperse but provides a smoother analysis for samples which have a broad size distribution extending over the majority of the size range covered by the range lens in use. You will typically use this analysis mode for measuring dry materials such as cement or soil. Compressed range analysis has a reduced upper size limit and is meant for use with dry powder and spray measurements. The compressed range analysis disables the use of Kill Data low. This analysis is only used on the Mastersizer S. To select an analysis mode: Select Analysis from the Setup menu. The screen below will appear. ILL 2061 Make your choice of analysis from the Analysis model section of the dialogue box. For this demonstration select polydisperse. All other choices on the screen, such as kill data and Particle density are for the advanced user only. Select OK. Page 5.2 M A N

75 CHAPTER 5 Remember - unless you definitely know that the result graph will be of a particular shape always use the polydisperse model. Choosing the correct presentation As stated in earlier chapters the Mastersizer uses the Mie theory to calculate the size of your sample. The Mie theory requires some knowledge of the optical characteristics of the sample and the medium it is dispersed in - in particular their refractive indices. This information is used to calculate a predicted scattering pattern that the sample would generate when the analyser beam is passed through it. This predicted scattering pattern is known as a presentation. The choice of presentation can be one of the most difficult decisions to make when using the Mastersizer. Saying this, if you are in any doubt you can use one of the default presentations as these have been chosen to give a middle of the road setting and in most situations this is more than adequate. It should be noted that even if you only use the default presentations you would still get more accurate results when measuring small particles than using an instrument that only uses the Fraunhofer theory. If however you decide you need a more accurate result then you can use a presentation that is more closely matched to your sample. The Mastersizer system is supplied with many pre-calculated presentations based on the Malvern presentation grid. The Malvern presentation grid The Malvern presentation grid is a convenient method of labeling presentations. The presentation is labeled by a four character code of the form 3OHD. The presentation grid is shown on the next page - refer to this grid when reading the next section, which which discuses its contents. The first character is a number representing the instrument you are using. If you have a Mastersizer X then all your presentations will begin with 2 (for example 2OHD) or, if you have a Mastersizer S then all presentations will begin with 3 (for example 3OHD). In the following section the codes for the Mastersizer S (3) will be used in the examples. The second character represents the real refractive index of the particle relative to that of the dispersant. If your particle and dispersant has a relative real refractive index of 1.45 then the second character will be R, if it has a value of then the second character will be F etc. The values within the grid have been carefully G E T T I N G S T A R T E D Page 5.3

76 CHAPTER 5 G e t t i n g S t a r t e d chosen to give the widest choice of popular values. There are many reference books available that state the refractive indices of materials. Instrument First character Relative particle refractive index (real) Second character Relative refractive index (imaginary) Third character Dispersant refractive index Fourth characte r Mastersizer X A 0 A 1 A Mastersizer S B B 1.2 B C C 1.3 C D D 1.33 D E E 1.4 E F 0.01 F 1.5 F G 0.03 G 1.6 G 1.01 H 0.1 H 1.7 H I 0.3 I 1.02 J 1 J 1.03 K 3 K L M N 1.15 O 1.2 P 1.3 Q 1.45 R 1.65 S 1.95 T 2.35 U 3 V The third character represents the imaginary refractive index of the sample, (this is effectively its absorption). If the particle has an imaginary refractive index of then the third character will be E, if it has a value of 0.1 then the third character will be H etc. Choosing the value for the imaginary refractive index can be difficult as the value has to be calculated by performing an experiment. Page 5.4 M A N

77 CHAPTER 5 However, in most cases the value can be guessed with very little effect on the result. In practice you will probably only use two values; if the sample is transparent (glass beads for example) then there will be no absorption so the value will be 0 (A on the grid), otherwise use 0.1 (H on the grid) as the absorption value. If you feel you need a more accurate value then it can be calculated by following the procedure in appendix D. Finally the fourth character gives the refractive index of the dispersant the sample is suspended in. As an example, if the sample is suspended in air then the fourth character will be A (refractive index of air is 1) or if the sample is suspended in water then the fourth character will be D (refractive index of water is 1.33). Again, there are many reference books available that state the refractive indices of materials. In very rare circumstances you may find that the choice of presentation is critical to the results and the values on the Malvern presentation grid are not accurate enough. In this situation a presentation can be generated that use the exact figures for the refractive index etc. Methods of selecting a presentation There are several ways to select a presentation. A presentation is always selected through the Setup presentation dialogue shown below ILL 1872 This screen gives you three ways to select a presentation. These options are: The simplest way to select a presentation is to select one of the system presentations. There is a choice of four presentations usually you will only use one of the two standard presentations. Secondly, if you know the Malvern presentation code you can choose from the Select by code section. This lists all available codes that are currently on the system. G E T T I N G S T A R T E D Page 5.5

78 CHAPTER 5 G e t t i n g S t a r t e d The right side of the screen gives the option of selecting or generating a custom presentation. The list gives a choice of four of the custom presentations available. Selecting the Request button will allow you to select another custom presentation from those currently available. There is also an option for you to enter the refractive indices of a new sample and dispersant. When these details have been entered the software will give you the option to: Use a presentation that is the closest match from the existing presentations. Calculate a new presentation based on the values within the Malvern presentation grid. Calculate a new presentation based on the exact values entered. When is the presentation important? This is a difficult question to answer and usually depends on your own requirements. Creating a more accurate presentation can be very time consuming and the extra amount of accuracy may be minimal. If you are unsure of the benefit of using a different presentation it is best to try using two presentations close to the one required and see if the difference is acceptable. For example if you required a presentation that has not been generated, the software will tell you the closest presentation available. If you make an analysis using this presentation and then made a second analysis using the next available presentation (effectively making an analysis using a presentation from both sides of the actual presentation required) you can then examine the difference in the result. If the difference is minimal then you should use the closest presentation available. Remember that you can select an existing presentation and analyse the measurement data in a few seconds - it may take over an hour to calculate a new presentation for each lens! It is always best to check if neighboring available presentations are acceptable before generating a new one. There are two instances when the presentation becomes important. Firstly, when the size of the particles within your sample are under 10 microns. As the particles get smaller then the choice of presentation becomes more important. In general, if the particles are over 10 microns, then one of the system presentations will be adequate. Secondly the presentation becomes more important as the value of the refractive index of the sample and the dispersant become closer. In general if the refractive index of the sample divided by the refractive index of the dispersant is greater than 1.2 then the choice of presentation is not important - the system presentation should be adequate. Page 5.6 M A N

79 CHAPTER 5 The following is general advice on how important the choice of presentation is: If the ratio of the refractive index of the particle and the refractive index of the dispersant is greater that 1.2 and the size of the particles are over 10 microns then the choice of presentation is not important. If the ratio of the refractive indices is between 1.1 and 1.2 and the particle size is over 1 micron then the presentation is important. If the ratio of the refractive indices is under 1.1 or the size of the particles is under 1 micron then the presentation is critical. Contact Malvern for an appropriate model matrix. If the ratio of the refractive indices is under 1.1 and the size of the particles is under 1 micron then the presentation is critical. Contact Malvern for advice. The absorption of the particles also plays a role, the higher the absorption, the less critical is the optical model. However the above advice is good for any absorption. It should be clear to the user that for liquid sprays in gaseous atmospheres, and for dry powders the optical model dependence is not strong due to the high differential of the refractive indices involved. For these types of experiments the user will not find the choice of presentation is not critical and the standard presentation will be entirely adequate. It is worth pointing out in many cases it is possible to choose a different dispersant to create a high differential refractive index where difficulties are being experienced with the normal choice. Selecting a presentation For this demonstration we will assume that the system presentations are adequate. Details on selecting a custom presentation can be found in the Software reference manual. To select a presentation Select Presentation from the Setup menu. The dialogue below will appear. The sample you have just measured is dispersed in water so you will select the Standard - Wet system presentation. Select Load from the dialogue box. The software will load the selected presentation and return to the main screen. G E T T I N G S T A R T E D Page 5.7

80 CHAPTER 5 G e t t i n g S t a r t e d 1 2 ILL 2062 Special Presentations The system presentations contains two special presentations, Fraunhofer 3$$D and Reference Reticle 3$$1. There is also a third special presentation, 3$$A, that can be found when you select a presentation by using the Select by code facility. The two presentations 3$$A and 3$$D on your disc are the Fraunhofer presentations for samples dispersed in air with refractive index 1.0 (3$$A) and dispersed in water with refractive index 1.33 (3$$D). These are provided to allow the Mastersizer to be compared with other instruments that only provide the simpler Fraunhofer analysis. The Fraunhofer model is applicable with reasonable accuracy down to approximately 10microns. Below this it becomes systematically in error, to a degree which of course depends on the actual optical properties of the sample, with a tendency to overestimate the volume of fine particles. For this reason it is advisable to use one of the Standard model unless the measurement is specifically intended to be compared with other equipment which uses Fraunhofer scattering theory. A special presentation, 3$$1, is provided for use with the Malvern Diffraction Reference Reticle. Contact your Malvern Instruments representative, or see the Reticle manual, for more information. Calculating the result Once the optical model and presentation has been chosen the final procedure is to calculate the result. Page 5.8 M A N

81 CHAPTER 5 To calculate the result Select Calculate Result from the Measure menu. The Calculate Result dialogue box will appear. This dialogue is shown below. ILL 1927 The Calculate Result dialogue shows the progress of the analysis by displaying the residual. The residual is an indication of how well the presentation data is fitted to the measurement data and is given as a percentage. A final residual of under 1% shows a good fit. Once the calculation is complete the graph and table panes update to show the new result data. The final result can be displayed in many ways. You will now need to view the result to gauge whether the result is acceptable. G E T T I N G S T A R T E D Page 5.9

82 CHAPTER 5 G e t t i n g S t a r t e d Page 5.10 M A N

83 Viewing and printing the results C H A P T E R 6

84

85 CHAPTER 6 Introduction Now that you have measured your sample you can display and print reports of the results and data generated. This chapter runs through the options you have for displaying and printing the results. This chapter should be read in conjunction with the next chapter that gives advice on understanding the information within the results. By the end of this chapter you will be able to change the way the result is viewed and printed using the standard reports supplied with the Mastersizer. A detailed description of each of the views is given within the Software Reference manual. Views The information you have generated by analysing the measurement data is displayed on the screen. The data can be displayed in various formats - each format is known as a view. Malvern provides 11 standard views that can be quickly selected by opening the View menu. The View menu is shown below. ILL 1934 The first five views display the result data in different ways, for example some views display the data in a % under format (i.e. 15% of the sample is under 1.5 microns etc) and other views display the data in a % within size band format (i.e. 5% of the sample is between 1.2 and 1.6 microns etc). Other views arrange the data to be displayed within custom size bands so that the information measured on the Mastersizer can be compared to various standards. The ASTM E11:61 and BS410:1986 views for sieves, for example, display the data in a format that can be compared directly with these two sieve standards. G E T T I N G S T A R T E D Page 6.1

86 CHAPTER 6 G e t t i n g S t a r t e d Note:. It should be noted that the result data is never changed - it is only displayed in a different way. NOTE An alternative to selecting the Graph option from the Setup menu is to press the right mouse button when the cursor is over the graph pane. The sixth result view shows the current shape correction table. See chapter 10 for details on shape correction. As well as these first six standard views there are five other views available within the view menu. These last five views help you to inspect and compare the data and results. For example the Data view displays the measurement data before it has been analysed. The Fit view allows you to view how well the analysed data has been fitted to the measurement data. The Statistics and Difference views allow you to compare one result with another etc. The Parameters view shows the current settings of the instrument. There is no graph associated with this table. Most (but not all) views are separated into a table and a graph. The graph can be made to display the information in different ways by altering the settings within the Setup-Graph dialogue box. This dialogue gives you options on the way the graph is drawn. The Graph setup dialogue is shown below. ILL 1847 The Plot Types section of the dialogue allows you to plot the graph in various formats. For example the data can be plotted as a frequency curve, histogram undersize or an oversize plot. It is possible to select more than one plot type Page 6.2 MAN 0101

87 CHAPTER 6 so, for example, you could have the data plotted as undersize, oversize and as a histogram on the same graph. Other options within the dialogue allow you to change the format of the axis. Any changes made to the graph is reflected in the table pane. For example, if the graph is changed from plotting an undersize plot to a histogram plot then the table pane will change from displaying the data in an % under to % in band format automatically. If the result is modified by using some of the advanced analysis features discussed later in chapter 10 the results in the table pane are colour coded to highlight the data that is affected. The colours used are: Colour Black Dark Red Green Magenta Dark Blue Light Blue Represents Normal data and results Killed data and results Blended results Shape corrected results Extended results Transformed results Each view is produced using the Malvern page description language which is a sub-set of the Mastersizer Basic language. It is possible for the advanced user to create their own views to display the information in a format specific to their own requirement. New views can be assigned to the View menu - see Setup-Table in the software reference manual for details. Reports Each of the standard views that is provided by Malvern has a corresponding print report that will allow you to print the data within the view. Each report is designed to suit A4 size paper. The report contains the same information as in the table and graph panes except that up to 4 lines of sample documentation are also included in the report. As with the table pane above, any result modification will be colour coded on the printed report using the same colour codes as above. G E T T I N G S T A R T E D Page 6.3

88 CHAPTER 6 G e t t i n g S t a r t e d If you are an advanced user you can also customise the report to display the information to suit you own needs using the Mastersizer Basic language. See the Malvern Basic Reference manual (MAN 0103) for more information. To print a report To print a report of the view you are currently in select the Print item in the File menu. When selected the dialogue below will appear. ILL 1866 NOTE An alternative to using the File-Print menu item is to select the Print button. The dialogue gives you the option to print either one or more from the choice of; a report, graph, table or a view of the whole screen. If you wish to print a graph you will have further options on whether the graph is printed on a full page, half page or third of a page. Further information on printing is given at the end of this chapter in the section Understanding printing. This section will go into more detail on how to optimise the print out and how to install and setup a printer. If you are reading this manual for the first time you may feel that this information will not be of much benefit at present. If, however, you are experiencing difficulties with printing you may find this section useful. Overview of the standard views and reports This section describes the contents of the standard views and reports. More detail on understanding the information is described in the next chapter. For a detailed description of the Views see the Software Reference manual. It should be noted that these standard views are there for your convenience. They have been designed to give a wide choice of common methods of displaying the result data. You may never have to use some of the views, for example, if you do Page 6.4 MAN 0101

89 CHAPTER 6 not require your data to be presented in a format that can be compared to sieve measurements then you will never use the three standard views on sieve standards. The following section gives an overview of the views available. Take time to read through the section - you should be able to quickly identify the views that are not applicable to your type of analysis. View - Result 1 Analysis Sizes. This shows the result of the analysis in terms of the measurement size bands. This range is increased if the result is extended or blended. View - Result 2 Histogram Sizes. This shows a higher resolution than the analysis size bands. You can change the number and range of the size intervals. This range is increased if the result is extended or blended. View - Result 3 Derived Diameters. This shows various derived diameters, the distribution moments of volume, surface, length and number, the distribution percentiles and result modes. View - Result 4 ASTM E11:61 Sieves. This shows the standard ASTM sieve size bands. Size bands outside of the instrument range are shown in red. View - Result 5 BS 410:1986 / ISO 565:1990 Sieves. As Result 4 but for the BS 410 / ISO 565 sieve size bands. View - Result 6 Shape Factor. The shape factor correction terms for the current result. View - Data This view shows the light energy data as measured by the instrument. There are three columns, background signal (light without any sample added), signal (sample added) and data (signal minus the obscuration corrected background). View - Fit This shows the analysis fit to the data and the difference between them. View - Parameters This view shows various system parameters such as current file name, record number and measurement details etc - a graph is not shown. View - Difference This view shows the difference between the current result and a result set as the reference. An information message appears if no reference record has been set. G E T T I N G S T A R T E D Page 6.5

90 CHAPTER 6 G e t t i n g S t a r t e d Understanding printing This section goes into more detail on the subject of printing. If you are reading this manual for the first time you may feel that the information within this section will not be beneficial at this point. If so, go onto the next chapter. Printing in Windows is page based. That is, a page must be complete before printing will start. Because of the Multi-tasking nature of Windows the printing can take place in the background, that is, at the same time as the user is doing something else. However, before printing can start the page must be made up and, because of Windows extensive use of graphics, this can take some time. To find out more about printing from Windows read about Print Manager in the Microsoft manual or start Print Manager from the Main group and use the Help system. To optimise printing requires a compromise between print quality and speed. To improve printing speed: Choose Draft Table Quality from the File-Print... dialogue box. This disables the drawing of lines and boxes in Tables and Reports. Pictures, such as Logos, are also disabled but the system graphs will still appear in Reports. All text information in tables will use the Draft font set up in Setup - Table... Choose a printer-resident font. The Draft font is usually a printer resident font. From the Setup -Table... dialogue box check the Draft Font radiobutton then select the Setup Font... button. The list of fonts include symbols to the left of the font name will appear. Printer-resident fonts have a picture of a printer. If you select a printer-resident font but still have graphic lines and boxes in the same area of the page then the printing may actually be slower, because the printer has to make one pass to do the graphics and another to do the text. Choose a lower resolution for graphics printing. Use the Microsoft Control Panel to change the resolution. With a lower resolution there is less information to print and hence it is faster. Disable colour printing. Dot-matrix printers with coloured ribbons require one pass of the print head for each of the 4 colours and hence are very slow. Change to a black ribbon and remove the check from the Use Colour checkbox in the File-Print dialogue box. Note that the Hewlett-Packard colour DeskJets are not substantially faster in monochrome. Once printing has started you have some control of the printing speed by altering the priority in Print Manager. The Priority setting is done from the Options menu. With high priority the printing will complete sooner, but other Page 6.6 MAN 0101

91 CHAPTER 6 applications, such as the Mastersizer software, will become less responsive to the keyboard and mouse. If you have sufficient memory installed you might consider installing a ramdrive. The Print Manager is able to use this area of memory for temporary spooling instead of writing files to the hard disc. To install a ramdrive please consult the DOS manual provided with your system. Selecting fonts for graphs and tables The Graph fonts The graphs all use the same font for axes, labels and key table. The font is selected from the Setup - Graph dialogue box. Select the Font... button to produce the font selection dialogue box. Select a font name, style and size. Note that the title at the top of the graph is always a bold version of the font. Choose a True Type font as these give the best reproduction on most printers. If Scale Size with Graph is selected the size in the font size list box is ignored and the text size scales as a proportion of the height of the graph frame. This option is automatically used when transferring a graph to the clipboard, but it may also be of use if you reduce the size of the Mastersizer window while working in another application. The Table fonts To change the fonts for tables, the text part of reports and the footer of each printed page select Setup-Table. The section at the bottom of the dialogue box shows the font information. Up to four fonts may be used in a table or report. The recommended use for these font styles are: Normal font for table entries. Same size but bold, for headings. Same size and bold but italic or underlined, for showing values that are out of limits etc. Larger size for titles. Besides each font radio-button is an example of the current font style, but not the correct font size. The fifth font is marked Draft and is used for the footer of each printed page and replaces the other four fonts if Draft mode is selected when printing. G E T T I N G S T A R T E D Page 6.7

92 CHAPTER 6 G e t t i n g S t a r t e d See the Table Font dialogue in the software reference manual for details on changing a font. When selecting the Draft font you can choose a printer resident font (ones with a small picture of a printer beside their names in the font list box). These sometimes print faster and do not have to be represented on the screen. Note that the font size will have an effect on the size of the table. All the tables provided by Malvern use a line spacing set by the font in use. If the font size is increased the table will increase in length and may not fit on the screen or the printed page. A font size for Font 1 of 10 points or smaller should be used. Installing and selecting a printer If you want to print from the Mastersizer you must have a printer installed. If Malvern supplies the computer and printer then the printer will be already installed. If you are supplying your own printer then you must install a Windows printer driver compatible with your printer. To install a printer: Start the Microsoft Control Panel. This is in the Main window group. Select the Printer icon by double-clicking with the mouse or moving the highlight with the cursor keys and pressing the Enter key. Select the Add >> option. A list box is produced. Select your printer from the list and press Install... The Control Panel then gives you instructions on how to install the driver. Setting up a printer involves:- Selecting the Port. Setting resolution and paper size. Setting time-outs. To set up a printer: From the Control Panel Printer dialogue box select the Connect.. button. Select the port for the printer. This will generally be LPT1. If you have a serial printer remember that COM1 is used by default for the Mastersizer interface. To set other options such as time-out and re-try times refer to the Control Panel Help system. Select OK to return to the main screen. Page 6.8 MAN 0101

93 CHAPTER 6 Select the Setup... button. A dialogue box is produced that allows printer options to be changed. Refer to the Help system by selecting the Help button on this dialogue. Pay particular attention to the resolution setting. If you have installed more than one printer make the one you will use most of the time the default. Changing print settings Using the print options from the Mastersizer software has already been discussed briefly earlier in this chapter. That information is expanded upon within this section. By selecting the Printer Setup dialogue box using File - Printer Setup... you can change which printer to use and many printer options may be changed without returning to the Windows Control Panel. In particular:- Page Orientation. Tables and Reports look best if Portrait orientation is used. Full page graphs look best in a Landscape orientation. Changing the page orientation may have an effect on how tables look in the Table pane. Page Size. If your printer has more than one paper bin then the page size may be changed. Remember you may also have to adjust the Margins set in File - Print... Changing the page size has an effect on how tables look in the Table pane. Printing from the Mastersizer Using the File-Print... menu item or the Print Easy button will produce the print dialogue:- ILL 1848 G E T T I N G S T A R T E D Page 6.9

94 CHAPTER 6 G e t t i n g S t a r t e d From this you can select the content of the print. A Report is a single page summary of the result as a table of values, a graph and a summary of measurement conditions and sample details. The contents and style of this report are controlled by your choice in the Setup-Table menu item. The Graph print will be the graph for the currently selected View. The contents and appearance of this graph depend on your choice in the Setup-Graph menu item. The Table print will be the table for the currently selected View. The contents of this table depend on your choice in the Setup-Table menu item. The Window option allows you to print a copy of the currently active window. Page 6.10 MAN 0101

95 Interpreting the results C H A P T E R 7

96

97 Introduction This chapter sets out to give you guide-lines on the interpretation of the results that the Mastersizer generates. The first section explains some important concepts that you have to understand before proceeding. The second section runs through some of the terms and expressions that are used in the standard views. Fundamental concepts To understand the meaning of the results from the Mastersizer there are a number of fundamental concepts which may require explanation. These are: The results are volume based. The result is expressed in terms of equivalent spheres. The derivation of distribution parameters. Results are volume based CHAPTER 7 The first, and probably most important point to remember in interpreting results from a laser diffraction instrument is that the fundamental size distribution derived by this technique is volume based. This means that when the result lists, for example 11% of the distribution is in the size category microns this means that the total volume of all particles with diameters in this range represents 11% of the total volume of all particles in the distribution. It is useful to consider a numerical example on this point. Suppose, for simplicity, that a sample consists of only two sizes of particle. 50% by number having a diameter of 1 micron and 50% by number 10 microns. Assuming spherical particles, the volume of each of the larger particles is 1000 times the volume of one of the smaller ones. Thus, as a volume distribution, the larger particles represent 99.9% of the total volume. The graph below illustrates this for a more realistic distribution. The example below shows the result of transforming a skewed volume distribution to number. Of course, for a mono-size distribution such as a latex, 100% of particles of a particular diameter will still be 100% whether expressed by number or volume. G E T T I N G S T A R T E D Page 7.1

98 CHAPTER 7 G e t t i n g S t a r t e d 30 % Particle Diameter (µm.) ILL 1874 The Malvern software allows the result to be converted to other distribution forms such as a number distribution for example, but it should be remembered that the initial measurement is volume based and any subsequent conversions are liable to introduce systematic errors. Equivalent spheres The Mie theory presumes that the particles you are measuring are perfect spheres. In practice they are very rarely so. This causes a problem in the definition of the term measure the particles size - if the particle is an irregular shape which particular dimension do you measure? As an example, imagine that I give you a matchbox and a ruler and ask you to tell me the size of it. You may reply by saying that the matchbox is 50mm x 25mm x 10mm. You cannot say that the matchbox is 25mm as this is only one aspect of its size. It is not possible to describe the three dimensional matchbox with one unique dimension. Obviously the situation is even more complex for irregular shaped particles such as grains of sand or the pigment particles in paint. Most people want a single measurement to describe their sample i.e. they wish to say that their sample is made up of 50 micron particles for example. What is required is a unique number that describes the particle. There is only one shape that can be described by one unique number and that is a sphere. If we say we have a sphere of 50 microns, this describes it exactly. We cannot do the same even for a cube as 50 microns can refer to its edge or to a diagonal. One way to get a single unique number to describe your irregular shaped particle is to compare some feature of the actual particle to an imaginary spherical particle. Some typical methods of doing this are: Page 7.2 MAN 0101

99 CHAPTER 7 Equivalent surface area. You can calculate the diameter of a theoretical sphere that has the same surface area of the original particle. Equivalent maximum length. This is where the diameter of a theoretical sphere is the same as the maximum dimension of the original particle. Equivalent minimum length. This is where the diameter of a theoretical sphere is the same as the minimum dimension of the original particle. There are many other methods available to do this. This technique is known as equivalent spheres. The Mastersizer uses the volume of the particle to measure its size. In the example above the matchbox has a volume of 50x25x10mm = 13750mm 3. If the Mastersizer was able to measure this size of particle it will take this volume and calculate the diameter of an imaginary particle that is equivalent in volume - in this case it will be a sphere of 30mm diameter. Obviously you will get a different answer if you where using the surface area or maximum dimension of the matchbox to calculate an equivalent sphere. All of these answers are correct but each is measuring a different aspect of the matchbox. We can therefore only seriously compare measurements that have been measured using the same technique. Derived distribution parameters The third point is that the analysed distribution is expressed in a set of size classes which are optimised to match the detector geometry and optical configuration giving the best resolution. All parameters are derived from this fundamental distribution. Distribution parameters and derived diameters are calculated from the fundamental distribution using the summation of the contributions from each size band. In performing this calculation the representative diameter for each band is taken to be the geometric mean of the size band limits: d i l di This number will be slightly different to the arithmetic mean: d + i l d 2 i For example the size band microns has a geometric mean of microns and arithmetic mean of microns. In most cases the difference is small but the geometric mean is chosen in these calculations as more appropriate to the logarithmic spacing of the fundamental size classes. G E T T I N G S T A R T E D Page 7.3

100 CHAPTER 7 G e t t i n g S t a r t e d The same principle of calculation applies to the distribution statistics standard deviation, skewness and kurtosis. For mono-size distributions such as latex the distribution mean is reported as the geometric mean of the size class and standard deviation, skewness and kurtosis are reported as zero. The procedure used for other parameters of the distribution is to create a spline fit to the fundamental result. Intermediate values are then read off this curve allowing interpolation of percentile points which do not coincide with the measurement size band boundaries. Understanding the tables and graphs When you have finally completed your analysis you will probably print out a report from one of the standard views described in the previous chapter. Many of the measurement statistics and information given are common to most of the views. Within this section we will explain in simple terms the meaning of these items, and where possible, give advice on the ideal values they should be reporting if your analysis is correct. The result from the analysis is the distribution of particles using the set of size classes that have been determined by the design of the detector. The detector has been designed for the optimum arrangement of size classes. It is from this basic distribution that other statistics are calculated. As stated above, a spline curve is also fitted to the basic result that allows a result from in-between the size classes to be determined. The various graphs and report types such as oversize, undersize, frequency curve and histograms are obtained from this fitted curve. 20 Volume % Particle Diameter (µ m.) The graph above shows the various graph types available. 0 ILL 1869 Page 7.4 MAN 0101

101 CHAPTER 7 The undersize curve takes the form of the percentage below a certain size for example 20% (reading the figures from the right hand scale) of the sample is under 40 microns etc. The oversize curve takes the form of the percentage above a certain size for example 80% of the sample is over 40 microns etc. Again the oversize plot uses the right hand scale to take its percentage scales. The frequency curve is obtained by differentiating the cumulative undersize curve. The peak of the frequency curve gives the modal diameter - the most commonly occurring particle diameter. Note that the frequency curve is scaled to be approximately the same height as the analysis size band histogram. The histogram plot shows the percentage of the volume of the sample that is within a particular size band (% in). Histogram plots use the left hand scale. It is the height of the histogram bars that are of interest, not the area under the bar. Each bar represents a size band of particles - on the initial analysis the size bands are determined by the physical design of the detector. Once analysed the user can set the number of size bands. A typical report is shown below, followed by a brief description of the key features. 3 Result: Analysis Table ID: Sample D Run No: 1 Measured: 9/08/94 14:52 File: MSSTEST Rec. No: 3 Analysed: 9/08/94 14:54 Path: C:\SIZERS\DATA\ Source: Analysed Range: 1000 mm Beam: 2.40 mm Sampler: None Obs': 10.3 % Presentation:3$$D Analysis: Polydisperse Residual: % Modifications: None Conc. = %Vol Density = g/cm^3 S.S.A.= m^2/g Distribution: Volume D[4, 3] = um D[3, 2] = um D(v, 0.1) = um D(v, 0.5) = um D(v, 0.9) = um Span = 0.43 Uniformity = 0.14 Size Volume Size Volume Size Volume Size Volume (um) In % (um) In % (um) In % (um) In % ILL 2063 The residual, as stated earlier, is an indication on how well the analysis data was fitted to the measurement data. A good fit is indicated by a residual of under 1%. If the residual is over 1% then this may be an indication that you have not G E T T I N G S T A R T E D Page 7.5

102 CHAPTER 7 G e t t i n g S t a r t e d used the correct presentation. Try re-analysing the measurement data with a new presentation. The statistics of the distribution are calculated from the results using the derived diameters D[m,n] - an internationally agreed method of defining the mean and other moments of particle size. See British standards BS2955:1993 for more details. D(v, 0.5), D(v, 0.1) and D(v, 0.9) are standard percentile readings from the analysis. D(v, 0.5) is the size of particle at which 50% of the sample is smaller and 50% is larger than this size. This value is also known as the Mass median diameter (MMD). D(v, 0.1) is the size of particle for which 10% of the sample is below this size. D(v, 0.9) gives a size of particle for which 90% of the sample is below this size. D[4,3] is the volume mean diameter. D[3,2] is the surface area mean diameter. Also known as the Sauter mean. Span is the measurement of the width of the distribution. The smaller the value the narrower the distribution. The width is calculated as: d b09. g db01. g db05. g Concentration. This is the volume concentration. It is calculated from the Beer-Lambert law and is expressed as a percentage. Distribution. This tells you the type of distribution the analysis has used. The options for this is set in the Result modification dialogue in the Setup menu. Options include change from volume to surface area, length or number. It must be remembered that the Mastersizer measurement is fundamentally a volume distribution - transforming the result into a surface, length or number distribution is a mathematical process that may amplify any error in the original result. Obscuration. The obscuration helps set the concentration of the sample when it is added to the dispersant. It is a measure of the amount of laser light lost due to the introduction of the sample within the analyser beam. An ideal range is between 10 and 30%. Uniformity. The uniformity is a measure of the absolute deviation from the median. Page 7.6 MAN 0101

103 CHAPTER 7 SSA (Specific Surface Area) The specific surface area is defined as the total area of the particles divided by the total weight. If you are using this value then it is important to set the density of the sample from the Setup-Analysis dialogue. G E T T I N G S T A R T E D Page 7.7

104 CHAPTER 7 G e t t i n g S t a r t e d Page 7.8 MAN 0101

105 Automating the process C H A P T E R 8

106

107 CHAPTER 8 Introduction The manual so far has taken you through the individual steps of making a measurement and processing the data. This has allowed you to understand the individual processes involved. In practice however you would most probably set up the whole measurement sequence as a semi-automatic process. NOTE The Measurement Setting up a sequence A sequence is set up through the Setup-Measurement Sequence menu item. The Measurement sequence dialogue is shown below. Sequence dialogue can also be selected by pressing the Setup Sequence button. 1 2 ILL 1876 From this dialogue you can select the measurement procedures you require. You have the option of running more than one measurement by increasing the Number of Measurements edit box. A delay can also be set in between the measurements. This is useful, for example, if you wish to automatically measure the same sample over a period of time. Once you have set up the measurement details you can set the way the measurement data will be analysed by pressing the Process Sequence Setup button. The dialogue below will appear. G E T T I N G S T A R T E D Page 8.1

108 CHAPTER 8 G e t t i n g S t a r t e d ILL 2015 NOTE An alternative to selecting Measure-Start sequence is to press the Start Sequence button. The options within this dialogue allow you to analyse the measurement data (using the analysis model and presentation currently selected in the Setup - Analysis and Setup - Presentation menu items) and save the results for each measurement that the sequence makes. Other options allow you to perform various statistical calculations. Once set up the whole sequence can be started by selecting the Measure-Start Sequence menu item. The measurement window during the sequence is similar to that when a measurement is carried out manually. The Previous button is removed because you cannot move backwards through the sequence. If the Pause between Stages checkbox is set in the Setup-Measure Sequence dialogue ( in the diagram at the beginning of this section) then clicking the Next button will move the measurement on to the next stage, otherwise the progress through the stages happens automatically. The figure below shows part of the Measure Window during a sequence. (Note that the pause status can not be changed after the sequence has started) ILL 2016 Clicking the Close button will terminate the sequence and display the message: Page 8.2 MAN 0101

109 CHAPTER 8 ILL 2017 Click No if you want to stop the sequence. If a delay has been set between cycles of the sequence and the time of the measurement is less than the delay time then a window appears to count down the remaining time. ILL 2018 Click the Cancel Timer button to continue directly with the next cycle or Abort Sequence to return to manual control. More details on setting a sequence can be found in the software reference manual. G E T T I N G S T A R T E D Page 8.3

110 CHAPTER 8 G e t t i n g S t a r t e d Page 8.4 MAN 0101

111 Sample preparation C H A P T E R 9

112

113 CHAPTER 9 Introduction Now that you have successfully made a measurement and analysed the result, we shall return to the important subject of sample preparation. The preparation of the sample before it is added to the system can be critical. Over half the problems encountered when measuring a sample are caused by bad sample preparation. If your sample is sticking together, dissolving, floating on the surface or if you have failed to get a representative sample you will not get a correct result. There are many techniques available to ensure that the sample is prepared successfully. Once you have found a suitable dispersion technique for your sample you can standardise the procedure so that comparisons can be made between samples. The information given in this chapter does not assume you are using an Automated Sample Dispersion Unit - information is given on wet and dry measurements. Representative sampling When taking a sample for a measurement it is most important to ensure that the sample you are using is representative of the whole sample. If the sample is taken from a bottle or container then care must be taken to ensure that the sample is thoroughly mixed. When the sample is a powder large particles tend to rise to the top of the container, as smaller ones fall to the bottom (as can be seen in the diagram below) ILL 2064 The large particles in the bottle of powder migrate to the top in transit. G E T T I N G S T A R T E D Page 9.1

114 CHAPTER 9 G e t t i n g S t a r t e d As the bottle vibrates in transit, large particles part to allow fine particles to fall through and then close together over the fine particles - being lifted in the process. In most samples there are some large particles and some small, but the majority fall in-between these two. If a sample is taken from the top of the container, then only the large particles will be measured. If this is then compared to a measurement with the sample taken from the centre of the container then the results will be different. If the sample is stored in a container then mix the sample thoroughly. Do not shake the container as this often increases the separation of the particles. Instead, hold the container in both hands and gently roll the container, continually changing its orientation. If the distribution of particles within a sample is particularly broad, then representative sampling can be difficult. If you are experiencing problems then the use of a spinning riffler may be beneficial. A spinning riffler uses the same principle that causes the sample to separate when it is kept in a container. The riffler comprises of a vibrating hopper which vibrates the sample down a shute. The act of vibrating the sample causes the larger particles to separate out and travel down the shute first. At the end of the shute is a collection of rotating plates that collect the sample evenly. When all of the sample has passed down the shute then each collecting plate will contain a representative sample. Liquid samples can also separate out if stored in containers, with larger particles sinking to the bottom. Again the sample should be thoroughly mixed if you are to get a representative sample. Sample splitters/rifflers are also available for liquid samples. Considerations for dry samples The first step when analysing a sample for the first time is to decide whether to analyse the sample in a wet or dry state. This is usually determined by the nature of the end use of the sample. If the product is to be used and stored in a dry form, for example sand, then perhaps a dry analysis is preferred. Another consideration is whether the material in its dry state is free flowing. Good pouring characteristics indicate a non-cohesive powder which will usually disperse well in a dry powder feeder without any difficulties, whereas a highly cohesive material tends to stick and clump together giving biased readings. The sample clumping together can often be overcome by drying the sample in an oven or by placing in a desiccator until dry and then continuing with the Page 9.2 MAN 0101

115 CHAPTER 9 measurement. Obviously care should be taken with delicate materials where drying in the oven may damage the sample. A fresh sample that has not had time to absorb moisture from the atmosphere is always preferable and will usually give better results. Some samples can only be measured in a dry state as they react with all wet dispersants, for example they may dissolve or the particles may swell when in contact with a liquid. Considerations for wet samples The above are considerations to make when analysing a dry sample. Even more care should be taken when analysing a sample in a wet medium as there are more choices to be made. Choice and preparation of the dispersant The first choice to consider when measuring a wet sample is the choice of suspension medium (dispersant). When analysing a sample for the first time, it is always best to check the dispersion before hand. Add the selected dispersant (for an initial measurement it is usual to use water) to a little of the sample in a beaker and visually note the result. The sample may dissolve, this can usually be seen visually, or if unsure, analyse the sample and observe the obscuration figure. If the obscuration figure is seen to decrease then the sample is probably dissolving. The dispersant may itself contain impurities or particles that could be significant. You are recommended to filter your dispersant before use either with an in-line pipe filter or, for small quantities, a syringe based disposable type. Filtration to 1 micron is generally adequate with 0.22 microns being commonly available and an ideal size. If your dispersant is stored under pressure, or low temperature then you may also have to consider degassing before use. The pressure release, or temperature rise will reduce the solubility of gasses resulting in the formation of bubbles in the pipes and tanks etc. Bubbles are a problem as they are measured with the sample and are counted as particles - biasing the results. This is particularly a problem with some mains water supplies. The simple answer is to store sufficient dispersant at room temperature and pressure for several hours before use to allow the de-gassing to occur. It should also be noted that the use of cold dispersant in a warmer environment can also give rise to condensation on the outside surfaces of the cell windows. For systems plumbed into the mains supplies a small header G E T T I N G S T A R T E D Page 9.3

116 CHAPTER 9 G e t t i n g S t a r t e d tank will be suitable. Filter this water prior to use. Another solution is to warm the dispersant (for water typically to o C) and then allow to cool before use. Warning The practice of warming dispersants to allow de-gassing should not be attempted on volatile dispersants. Never allow dispersants to reach their boiling points. When analysing particles suspended in a liquid dispersant, one of the most important decisions is which liquid to use. The dispersant can be any clear (at 633nm wavelength) optically uniform liquid that does not interact with the sample causing it to change its size. Clearly you wish to use the safest, lowest cost solutions that are effective. Particles that give problems in one medium, such as dissolution, may be quite suitable in another. In all instances where difficulties in dispersion are experienced consider the option of another dispersant. The list below gives the commonly used dispersants (together with their refractive index for presentation calculations). Dispersant Refractive index Water 1.33 Ethanol 1.36 Propan-2-ol (Isopropyl-alcohol) 1.39 Acetone 1.36 Butanone 1.38 Hexane 1.38 Dimethyl Digol 1.41 The cost of some of the organic dispersants may limit its use to the Small Volume Sample Dispersion Unit that typically only uses 100ml of dipersant. Also the problem of the safe disposal of the sample after measurement must also be considered. Always adopt the correct procedures for disposing of the sample and dispersant, following any local guidelines. Most local regulations forbid hazardous samples and dispersants to be tipped down the drain, allowing it to enter the water system. Page 9.4 MAN 0101

117 Surfactants and admixtures If you are experiencing problems such as the sample floating on the surface of the dispersant then the addition of a surfactant or an admixture may be helpful. The next section briefly explains the use of these additives. Surfactants CHAPTER 9 The addition of a surfactant may assist the preparation of the sample by removing the surface charge effects on the sample that cause it to float on the surface or clump together. Surfactants have to be added in minute quantities, typically one drop per litre of dispersant. If too much surfactant is added to the dispersion tank then the action of stirring and pumping the sample may cause it to froth, entering bubbles into the system. Bubbles are measured by the system as particles which can bias the results. Anti-foaming agents may be added to prevent the formation of bubbles. Try adding a drop of surfactant to a quantity of sample and dispersant mixed in a small beaker. If the sample sinks to the bottom of the beaker in large clumps then discard the sample and start again. Try again, this time adding the sample to a dry beaker and adding a drop of surfactant and mixing thoroughly. Add the dispersant and mix well. This usually avoids the agglomeration caused by adding the dispersant first. A list of recommended surfactants in order of common use is given below: Surfactant Nonidet P40 Teepol L Synperonic N Aerosol OT Sodium dodecyl sulphate Hyamine 2389 Nature Non-ionic Non-ionic Non-ionic Anionic (solid) Anionic Cationic G E T T I N G S T A R T E D Page 9.5

118 CHAPTER 9 G e t t i n g S t a r t e d Admixtures Admixtures also aid dispersion by modifying the properties of the dispersant itself that are responsible for the problem. Admixtures are added in larger quantities, typically 1g/l. A list of commonly used admixtures is given below: Sodium Hexametaphosphate Sodium Pyrophosphate Trisodium Phosphate Ammonia Sodium Oxalate Calgon Calcium Chloride As these are solid materials dissolved into the dispersant the solution should be filtered after preparation to remove impurities. Slurries The act of mixing up a small quantity of concentrated sample, dispersant and additives before it is added to the instrument tank is known as preparing a slurry. Once the particles have been successfully dispersed into a slurry, then the sample may be added to the instrument without any further additions of surfactants etc. to the instrument dispersion unit. The problem of the sample settling out within the beaker can be solved by using a pipette to continually stir the sample. At the same time as stirring you can continually fill and empty the pipette. Use the pipette to add the sample to the dispersion tank. The use of ultrasonics In addition to the processes above ultrasonics can be applied to help the dispersion whether or not it contains a surfactant. When mixing the sample in the suspension medium, a visual inspection will often indicate whether ultrasonics are necessary. If there are large agglomerates of particles which sink to the bottom of the beaker, then try applying two minutes of Page 9.6 MAN 0101

119 CHAPTER 9 ultrasonics by placing the slurry and its beaker into an ultrasonic bath. It will be apparent if this has been effective. Further ultrasonics can be applied when the sample is added to the tank, if necessary. This will often prevent re-agglomeration, but is not always necessary. Caution Be wary of using ultrasonics with fragile particles as the ultrasonic action may actually break up the particles themselves. If in any doubt, microscopic observation before and after ultrasonics should establish whether it has been beneficial or not. Samples with unstable concentrations When adding the sample to the tank using the measure-inspect facility of the software you will occasionally experience obscurations that change during the dispersion period. Most samples will disperse very quickly so you will not notice the obscuration value rising. With some samples however the slow dispersion of the sample can be clearly seen. A measurement should not be made until the obscuration has stabilised - indicating that the sample has properly dispersed. The obscuration and its behaviour during the dispersion of the sample can also warn of other potential problems. If the obscuration decreases then the size of the particles within the sample may be increasing, either the sample is sticking together or the particles are actually swelling due to the dispersant. Other causes could be the larger particles settling out due to inadequate pumping and stirring or even the particles dissolving. If the obscuration increases rapidly it could be that particles are attaching themselves to the cell windows due to surface charges. The material is therefore in the analyser beam continuously and the obscuration appears to increase. To solve this problem use an appropriate admixture. Bubbles Bubbles have been mentioned earlier in this chapter. To the Mastersizer optics all bubbles are seen as particles and are therefore measured. You should always be wary of bubbles within the system. G E T T I N G S T A R T E D Page 9.7

120 CHAPTER 9 G e t t i n g S t a r t e d Bubbles can be tested for by circulating the dispersant with appropriate additives through the cell using the dispersion unit, and turning on the ultrasonics. Should bubbles pass through the cell and scatter light then you have a problem. The solution is to use the ultrasonics for one or two minutes, then turn them off and wait for several minutes with the sample continually circulating. Bubbles will vary in size but will typically be in the region of 100 microns in size. In many cases these bubbles can be clearly seen as a second and separate peak when the measurement data is analysed. Summary of sample preparation The flow diagram below shows the route taken to prepare an unknown sample. SAMPLE Does Ultrasound Work? For Dry Analysis For Wet Analysis No Yes Representative Sample (riffle if necessary) Analyse Yes Ultrasound If Necessary Analyse Representative Sample (mix well or riffle if dry powder) Does It disperse In Water? Yes No Does It Float? No Try Solvent e.g. Ethanol Propan-2-ol (IPA) Methanol Acetone Butanone (Methyl Ethyl Ketone) Hexane Toluene Dimethyl Digol Ultrasound If Necessary Analyse Analyse Try Surfactant Does This Disperse It? Yes No ILL 2019 Page 9.8 MAN 0101

121 Advanced result processing C H A P T E R 1 0

122

123 Modifying results The result produced by the analysis may be modified in a number of ways before it is presented in the graph or table. The modifications are controlled from the Setup-Result Modifications dialogue. In this dialogue you have the option of setting the modifications so they are applied to the current result only, or to the subsequent measurement results. The modification setup is saved with each result record and can be loaded for alteration. The modifications to the standard result are: Blend Results - two results of the same sample measured with different range lenses can be blended to produce a result across two size ranges. Shape Correction - the Mastersizer size range can be modified to make the result comparable with that from other sizing methods. Extend Result - results from other sizing methods can be added to the Mastersizer result to extend the result range. Transform Result - the default volume distribution result is transformed to surface area, length or number distributions. Kill Result - one or more result channels can be removed to isolate a result or remove the effects of noise. Kill Data - One or more data channels can be removed from the analysis, limiting the effects of bubbles and other contaminants, such as propellant gasses during spray measurements. This modification is carried out as part of the result calculation. Each of these modifications will now be discussed in detail. Killing channels Killing data channels CHAPTER 10 The analysis normally uses all the data channels. There are, however, some types of measurement in which it is inherently impossible to obtain all channels measured accurately. These channels are removed from the analysis by setting the kill data ranges to exclude a few channels at the lower or upper end of the range. G E T T I N G S T A R T E D Page 10.1

124 CHAPTER 10 G e t t i n g S t a r t e d It is important to realise that if these parameters are set unnecessarily the accuracy and resolution of the analysis will be reduced. Do not set kill channels at the lower end of the range to exclude data routinely unless you have good reason. For example in some spray measurements the presence of a propellant material imposes on the signal a scattering pattern of its own. This signal is only present at the same time as the sample and so cannot be compensated for by the background subtraction. In such cases the effects are frequently confined to a small angular range and it is desirable to exclude that range from the analysis. Unexpectedly large signals in these channels are more likely to be due to excessive bubbles in the dispersion, bad alignment or dirty optics. Large signals in the outer channels may well result from allowing high levels of daylight or artificial light to fall on the receiver optics during spray measurements. If spray measurements have to be conducted at a distance from the range lens such that the one or more outer rings of the detector are cut off then you should kill these rings to stop possible bias in the results. See Avoiding lens cut off in chapter 4 for more details. Up to ten data channels may be removed from the inner (lower numbered) and outer (higher numbered) data channels. The channels are counted from each end of the range so it is not possible to kill a lower numbered channel without also killing the channels below it, or a higher numbered channel without killing the channels above it. Killing a channel is not the same as putting the value to zero - the killed channel is actually excluded from the analysis. Below is an example of how killing data channels affects the result. The left hand display shows the measured data and on the right is the corresponding result. The data from the 50 microns particle distribution has been corrupted by scattering from bubbles - showing up as high readings in the first three channels. This produces the peak at 220 microns in the result. The lower displays show what happens if the first three channels are killed. The result display now shows the expected distribution. Page 10.2 MAN 0101

125 CHAPTER % Particle Diameter (µm.) % Particle Diameter (µm.) ILL 1879 The data channels may be killed by either using the Setup-Analysis dialogue or by adding kill cursors to the data graph, as shown below. Both of these methods create a new result with the channels killed. Alternatively you can set the killed channels during the inspect phase of the measurement, as shown in the section on Measure-Inspect in the Software reference manual. Killing result channels If it is not possible to remove the effects of contaminants and bubbles by killing data channels then the alternative is to kill the result channels. These contaminants form extra modes or peaks in the result after the analysis. By killing result channels the characteristics of the expected result distribution are isolated. In a similar manner to killing data channels, only channels at either end of the size range may be killed. Any number of channels may be killed as long as at least one channel remains unmodified. Unlike killing data channels the killed result channels are simply zeroed and the remaining distribution re-normalised. An alternative use for the kill result facility is to isolate a mode of the distribution so that the characteristics of that mode may be obtained separately from the complete distribution. This is particularly important if you are also transforming the result, where small modes, caused by errors, in the volume distribution are magnified and can become dominant when transformed to a number distribution. See Transforming Result Type later in this chapter. The result channels may be killed by either using the Setup - Result Modifications dialogue or by adding kill result cursors to the result graph. G E T T I N G S T A R T E D Page 10.3

126 CHAPTER 10 G e t t i n g S t a r t e d Using the Kill cursors The kill cursors are produced by depressing the left mouse button with the cursor in the left or right margin of the graph and then dragging the mouse towards the centre of the graph. You will have to be in the Data view to use the kill data cursors. When the grey cursor is at the correct position release the mouse button. A small dialogue appears on the screen. At this point you can choose to either; move the other cursor onto the graph, click the Apply button or Cancel the operation. ILL 2020 For the kill data option the Apply button starts an analysis to produce a new result with the required data channels removed. For the kill result option a new, modified result is produced. Shape correction - Changing the size calibration Each method of particle size measurement is likely to produce different results when measuring the same sample. This is because different particle sizing methods measure different physical characteristics of the particle. The particle diameter is then implied by using some theoretical connection to the measured parameters. Even image analysis can only produce an indisputable diameter for a particle if it is spherical and every particle in the sample must be spherical for the distribution parameters to be correct. If you have measurements on a sample from an alternative particle sizing method and wish to compare these with the results of the Mastersizer then you can use Shape Correction to modify the characteristics of the Mastersizer so it measures the same as the alternative method. The modification method is called Shape Correction because the Mastersizer uses a light scattering theory to convert measured data to a size distribution result and the theory depends on the particles being near spherical. For non-spherical particles a correction can be applied. Page 10.4 MAN 0101

127 CHAPTER 10 The Shape Correction works by modifying the size boundaries of each measurement class, which are originally defined by scattering theory and the geometry of the optics and detector. The action of the shape correction is to change these size values - in effect changing the calibration of the Mastersizer. To simplify the calculation of the terms the shape correction is limited to a linear transform between size classes: d' i= Ad i i + Bi where d i is the corrected size of class i and d i is the original size value. A i and B i are the shape correction terms. The A i and B i terms can be calculated by using the following method: 1. Draw a cumulative undersize curve on graph paper of the results of the alternative particle sizing method. 2. From the Mastersizer result list the size and cumulative result under that size. 3. From the list of Mastersizer result values find the corresponding size values from the graph of the alternative sizing method. 4. Draw a graph, an example of which is shown below, of the normal Mastersizer sizes d against d, the sizes found in stage Draw the best straight lines through one or more points. The slope of these lines are the shape terms A and the intercepts at zero d are the shape terms B. Below is an example of the graph drawn in stage 4. The dotted line shows an un-corrected result (A =1,B = 0). The points are sizes read from the result of the other sizing method. Two lines have been drawn through these points of slopes A1 and A2 and with intercepts at zero d of B1 and B2. When applying the generated shape correction terms to the Mastersizer size range values, A2 and B2 would be used for the upper 4 size values, and A1 and B1 for the lower 10 sizes. You can also see that there are two points, near the middle of the graph, that require a third line to be drawn with intermediary values. G E T T I N G S T A R T E D Page 10.5

128 CHAPTER 10 G e t t i n g S t a r t e d A2 d' µm 6 Slope = A1 Slope = A2 A1 4 B2 2 B dµm ILL 2021 The shape correction factors are stored as a shape file. The shape file can be created and edited using the Edit-Shape Factors dialogue. As the shape correction factors are generated for a specific Mastersizer size range, the correct range must be selected when creating and editing the shape file. The selected size range is also saved with the shape file. When a shape correction is required a shape file is selected and loaded during the process of modification. All shape files have extension.sha. Details of creating and editing shape files and selecting shape file for the result modification are described under Edit-Shape Factors and Setup-Result Modification in the Software reference manual. Extending the result If you want to measure samples with a broad range of sizes, some of which are above the size limit of the Mastersizer, then you may consider using the range extend facility. The Extend Result modification adds results measured by another method, usually by sieving, to those of the Mastersizer. To extend the result at least one measurement by the other method must lie within the measurement range of the Mastersizer. You need to calculate the cumulative result distribution using the other method ready for entering into the Mastersizer software. The values you will need are: The size for which 100% of the result is smaller. Up to 8 results, consisting of size and cumulative percent smaller, at sizes above the range of the Mastersizer. Page 10.6 MAN 0101

129 CHAPTER 10 At least one result within the range of the Mastersizer. The Mastersizer result will be scaled to be the percentage below the smallest of these sizes. The lower end of the Mastersizer may also be extended by entering manually a value in the smallest size band of the Mastersizer in place of the value calculated from the analysis. See the Setup-Result Modification command and the Extended Result dialogue in the Software reference manual for details of entering the extended result. Transforming result type The basic result produced by the analysis is a volume distribution which is the volume proportion in each size class of the total volume of the particles. It is possible to convert the distribution to a different type. Probably the next most useful distribution type after volume is that of number, where the number proportion of particle in each size class is the tabulated quantity. The other two types are surface and length distributions. The transformation can be expressed mathematically as: X i 100 Vi / d = V / d i where X i is the transformed percentage distribution, V i is the volume distribution result, d i is the mean size of class i and n is the required distribution type: 1 for surface, 2 for length and 3 for number. Note that a small volume of particles of small sizes can be transformed to a significant part of a number distribution. If this small volume is just due to noise, or other errors in the measurement, then it may swamp the actual desired distribution. These small errors in the measurement are, in effect, magnified by the transformation. You may consider using the Kill Result facility to isolate the significant part of the volume distribution before doing the transformation. See the Setup-Result Modification menu item in the Software reference manual for details on setting up a result transformation. n i n i G E T T I N G S T A R T E D Page 10.7

130 CHAPTER 10 G e t t i n g S t a r t e d 30 % Particle Diameter (µm.) ILL 1874 The example above shows the result of transforming a skewed volume distribution to number. Blending results In some cases the sample size range may be so broad that it cannot be covered by a single range lens but can be covered by the combination of two range lenses. The results measured by the two range lenses can be blended to produce a result with a broader size range. The blending takes place within the overlapped region of the two size ranges. The two results within this region are combined to give a smooth transaction of result from one size range to the other. In the following example the sample has a size ranging from 1 micron to about 3000 microns. When measured with the 300mm range lens of the Mastersizer S the results above 900 microns are cut off; whereas with a 1000mm lens the results below 4 microns are cut off. To get a result covering the entire sample size range, the results measured with the two range lenses are blended. 10 Volume% Diameter of particles (µm) 0 ILL 2798 Page 10.8 MAN 0101

131 CHAPTER 10 Of the two selected records the record with a smaller size range will be loaded as the current result ( in the graph above) and the one with a larger size range is marked as the blend record ( in the graph above). The blended result will have the smallest size of the first record and the largest size of the second record as its size range boundaries ( in the graph above). The number of results channels for the blended result is the same as the result with the smaller size range. Unlike other result modifications result blending is operated from the Open Sample File and Load Record dialogue. For details see the Software reference manual. Multiple modifications Sometimes you may want to apply more than one modification to a single result. This is achieved by setting up the required modifications from the Setup - Result Modification dialogue. The result is always modified in the order of Kill Results, Shape Correction, Extend Result and Transform Result. For a blended result only the extending and transforming modifications can be applied. Tromp curve analysis This technique is popular in the cement and mining industries for gauging the efficiency of classifiers and separators. View and report files MTROMP.PAG and MTROMP.REP are available in the Pages sub-directory which display the tromp curve. The analysis is done in program MTROMP.BSC which also assigns the page to View Result 8. Use the Control-Run Program command to load and run this program. When the program is run the current result should be the measurement taken at the output of the classifier. A result representing the feed distribution will be asked for by the program along with values for the feed rate input and product rate input in tons per hour. For more information on Tromp analysis ask your Malvern representative for the paper The Importance of Particle Size in the Cement Industry by Dr Alan Rawle. G E T T I N G S T A R T E D Page 10.9

132 CHAPTER 10 G e t t i n g S t a r t e d Page MAN 0101

133 Maintenance C H A P T E R 1 1

134

135 CHAPTER 11 Introduction The Mastersizer has been designed so that supervisor/operator maintenance is kept to a minimum. It should be fully understood that no one, except a qualified Malvern representative, should remove the transmitter or receiver covers of the instrument. The supervisor should only remove the sample area cover if spray measurements are to be performed and should only do so after reading the Health and Safety manual and the instruction manual for the spray accessories. Warning! Failure to follow these guidelines correctly could result in the emission of laser radiation. Laser radiation can be harmful to the body and can cause permanent eye damage. This section explains the routine maintenance procedures that the supervisor can perform. These procedures are: Replacing the sample tubes to and from the flow cell. Replacing the fuses. Cleaning and replacing the cell windows and window O rings. Cleaning the range lenses and beam expander. Cleaning the covers. An operator may perform all the above procedures except replacing the fuses. Replacing the sample tubing If organic solvents are regularly used as a dispersant you may find that the plastic tubing that connects the flow cell becomes hard and discoloured. To change the tubing simply pull it off the connecting pipes and replace with new tubing. G E T T I N G S T A R T E D Page 11.1

136 CHAPTER 11 G e t t i n g S t a r t e d Caution! When changing the tubing do not allow any dispersant or sample to come in contact with the instrument. Some dispersants and samples can cause permanent damage to the surfaces. The specification of the tubing is: Internal diameter - 3/16". External diameter - 5/16". Flexible - to allow the cell to be removed without having to remove the pipes. The tubing originally supplied by Malvern is Tygon R-3603 available from Cole-Parmer Instrument Company. Tygon is chemically compatible with a large range of materials. Contact the manufacturers for specific information on compatibility. If the tubing is to be replaced always replace with tubing of the same or better grade, in order to retain chemical compatibility. Always check the compatibility of new tubing with the dispersants and samples you are using before connecting and using the instrument. Replacing fuses Warning! Fuses must not be replaced by the operator. Only the supervisor or a Malvern representative should attempt to replace the fuses. If the Mastersizer system does not power-up, check the fuse. The fuse holder is located on the transmitter end panel next to the power input socket. Disconnect the mains power supply before unscrewing the fuse holder using a flat bladed screwdriver. The fuse and fuse holder can now be withdrawn. If the fuse requires Page 11.2 MAN 0101

137 CHAPTER 11 replacing simply pull the fuse out of its holder and replace with the appropriate fuse from the list below. The fuse required is: CSA applications (USA, Canada etc). 240V/110V, 1.25" 5A AS UL/CSA Rest of the world. 240V/110V, 20mm 2A AS Warning! Failure to replace the fuses with the correct size and value may result in hazardous operation. Cleaning the covers Caution! The surfaces of the system may be permanently damaged if samples or dispersants are spilt onto them. If a spillage should occur then the system should be disconnected from the power supply before scrupulously cleaning up the spillage. Periodically the covers and sample area should be thoroughly cleaned using a mild soap solution. Always ensure that the instrument is disconnected from the power supply and computer. Never use excess liquid to clean the instrument and always avoid electrical components (Connectors etc.). Always ensure that the instrument is completely dry before applying power. Never use a solvent based solution to clean the instrument as damage to the painted surface may result. G E T T I N G S T A R T E D Page 11.3

138 CHAPTER 11 G e t t i n g S t a r t e d Cleaning the optics The Mastersizer is a precision optical device. Cleanliness of the optics are fundamental to ensuring good measurements. It will occasionally be required to clean the cell windows, range lenses and the beam expander. One guideline for determining when the optics require cleaning is to observe the live display when making a background measurement. The display shows the values for each of the data channels. If any channel gives a value of more than 400 divisions then you are recommended to clean the optics. Caution! Always remove the lenses from the optical unit before cleaning. Do not however remove the actual lens from the lens holder as these are precisely set at manufacture. Cleaning the cell windows The flow cell is used as an example in this cleaning procedure. The removal and cleaning of the cell windows are similar on most cells used on the Mastersizer. Cleaning the system by rinsing through with fresh dispersant a couple of times is usually sufficient to prepare for a new measurement. Over time you will notice you cannot achieve such a good background measurement. That is the time to clean the cell windows. Make sure that the cell has been drained of dispersant then remove the cell assembly from the Mastersizer bulkhead. Disconnecting the two sample tubes from the cell. The windows are held in place by a metal retaining ring that can be unscrewed by using the window tool that is found in the accessory case. The cell windows are sealed by O rings. To remove a cell window: Locate the two pegs on the window tool into the two holes on the retaining ring. Rotate the window tool anti-clockwise and remove the ring. Page 11.4 MAN 0101

139 CHAPTER 11 If the O ring did not come out with the ring then carefully remove it with a pair of tweezers. Tip the window out of the cell onto a clean paper towel. The window assembly is shown in the diagram below ILL 2983 Inspect both sides of the cell window. If there are any signs of scratches the windows should be replaced. Spare windows may be obtained through your Malvern representative. At this point any dust on the surfaces of the window can be removed using a compressed gas duster can. Keep the can upright while in use to prevent liquid emerging. Caution! Do not wipe the windows with an ordinary dry cloth as this will cause scratches. Always use the procedure below to clean the surfaces. Inspect the windows by reflected light and see if there are any smears or prints on it. If so then you must wipe the lens surface using the following guidelines. Use a good quality lens tissue and gently wipe it over the surface once. Do not put your fingers on the lens during this wipe. Re-inspect the window and if still marked then repeat with another clean tissue. G E T T I N G S T A R T E D Page 11.5

140 CHAPTER 11 G e t t i n g S t a r t e d If this does not eliminate the mark then consider the use of a liquid cleaner such as Ethanol Absolute or Propan-2-ol. This can be soaked on a cotton wool bud and wiped across the window gently. Use one pass over the window and then discard to avoid scratching. Re-inspect the window and repeat until clean. The outer faces of the windows have an anti-reflective coating and are more prone to scratching than the inner surfaces. Be careful not to touch the faces of the windows or put them down on dirty surfaces. If the O rings shows any sign of damage they should be replaced. Re-assemble the windows by first fitting the O-ring to the retaining ring then pushing the window into position. (Place a piece of tissue over the window to prevent finger marks getting onto the surface.) The window has a chamfered edge and the side with the widest diameter must face outward. The diagram above shows this orientation. Screw the window ring back in place. Ensure the window is fully home in the mount and not held by the O-ring, otherwise the window will move when the pump speed is changed, causing the system to mis-align. Replace the cell onto the Mastersizer and reconnect the sample tubes. To check the integrity of the cell, pump dispersant through it. Check that no dispersant leaks from the cell or sample tube connectors. Note:. The cell windows are part of the optical system and removing them for cleaning will change their position. Remember to add an Align stage to your next measurement sequence or click the Align Easy button. Cleaning the range lenses The range lenses should not require cleaning often. If you find that you are getting poor background measurements then the lenses may require cleaning. The range lenses may be cleaned when removed from the optical unit. First remove dust from the lens without rubbing. An aerosol clean air duster or a camera blower brush are both suitable ways to achieve this. Inspect the lens by reflected light and see if there are smears or prints on it. If so then you must wipe the lens surface using the guidelines described in the section Cleaning the cell windows above. Page 11.6 MAN 0101

141 CHAPTER 11 Caution! Never remove the lens from the lens holder. The lens is precisely set at manufacture. Store the lens with lens caps on to avoid the need to repeat this procedure often. Cleaning the beam expander The beam expander will not require cleaning as often as the range lenses. Every 12 weeks however the lens should be carefully inspected for signs of dust. Always remove the beam expander for cleaning. Caution! Read the following instructions fully before starting to clean the beam expander. Failure to follow the procedure correctly may result in the improper functioning of the instrument. To clean the lens the aperture plate must be removed. This plate is a beam stop aperture that fits exactly around the emergent laser beam, helping to clean up stray light. It is precisely located and will need to be re-fitted in the exactly the same position on re-assembly. A simple means to achieve this is to mark the orientation of the plate with a pencil so that a line is drawn on the aperture plate and the beam expander body as shown in the figure below. Then loosen one locking screw only to release the plate. The front face of the lens may be cleaned by the same procedures used for the range lenses. G E T T I N G S T A R T E D Page 11.7

142 CHAPTER 11 G e t t i n g S t a r t e d 2 1 ILL 2073 When replacing the aperture plate, rotate the plate until the two pencil lines match up. Once in position tighten up the locking screw. Do not tighten any other locking screws. Caution! Failure to align the aperture plate in the exact original position will result in clipping of the laser. This will require a visit from one of Malvern s qualified service engineers or representative to rectify. The user should on no account attempt to re-align the aperture plate. Page 11.8 MAN 0101

143 CHAPTER 11 G E T T I N G S T A R T E D Page 11.9

144 Specification A P P E N D I X A

145

146 APPENDIX A Introduction This specification covers the Mastersizer in its most basic form i.e. without any details of the sampling accessories. Details on the specification of the accessories can be found in their individual accessory manuals. This specification covers both the Mastersizer X and Mastersizer S - any information that is specific to a particular model is given separately. Particle sizing specification The Mastersizer X has an overall size range of micron covered in four ranges. The Mastersizer S has an overall size range of microns covered in three ranges. The table below gives these ranges. Mastersizer X Mastersizer S Lens Size range Lens Size range 45mm µm 300RF µm 100mm µm 300mm µm 300mm µm 1000mm* µm 1000mm* µm * The 1000mm lens is only available on the long bench Mastersizers only. It should be noted that accessories may have individual size range limits that are more restrictive. Dynamic range. Accuracy. Measurement data :1 maximum for the Mastersizer S, and 800:1 for the Mastersizer X on a single measurement. ±2% on Volume Median Diameter (measured by an approved technique using a diffraction reference reticle). Up to 45 light energy measurements for the Mastersizer S and 31 for the Mastersizer X from a custom design semiconductor detector optimised for light scattering measurement. In addition a centre ring reading measures the unscattered light energy for determination of the obscuration. G E T T I N G S T A R T E D Page A.1

147 APPENDIX A G e t t i n g S t a r t e d Scattering angle range. Number of size classes. Primary output. Secondary output degrees (over the 3 ranges of Mastersizer S) degrees (over the 3 ranges of Mastersizer X ) degrees (over the 4 ranges of long bench Mastersizer X). Up to 100 uniformly spaced on logarithmic or linear plot or user selectable. Relative volume size distribution, diffraction energy data and laser beam obscuration. Relative volume concentration. Volume distribution on sieve size classes. Transformation of volume distributions to surface area, length and number distributions and reverse transformations. Derived diameters (D[4,3] to D[1,0]) which include volume, surface and number mean diameters. Sauter Mean Diameter. Volume distribution percentiles (user selectable). Moments of the volume, surface and number distributions, up to 4th (kurtosis). Documentation. Tabulated on screen. Plotted on screen. Stored/recalled to disc. Transferred over RS232. Printed reports. Optical unit specification Description. Laser transmitter. Transmitter and receiver units mounted on a rigid optical bed, with provision for mounting sample presentation cells & accessories. Minimum 2mW He-Ne Laser (633nm wavelength) with 18mm beam diameter, collimated and spatially filtered to a single transverse mode. Page A.2 MAN 0101

148 APPENDIX A Receiver for the Mastersizer S. Fourier transform lens mount. Range lenses of 300RF (reverse Fourier), 300mm and 1000mm (1000mm for long bench Mastersizer only). Composite detector array measuring a large angle range and two back scatter detectors in the 300RF range lens assembly. Detector carriage with motorised X-Y positioning under computer control for automatic alignment. Laser safety covers. Detector electronics. Receiver for the Mastersizer X. Fourier transform lens mount. Range lenses with 45mm (reverse fourier), 100mm, 300mm focal lengths and 1000mm for long bench Mastersizer X only. Detector on sliding rail carriage with automatic positioning at preset optical positions. Detector carriage with motorised X-Y positioning under computer control for auto alignment. Laser safety covers. Detector electronics. Detector for the Mastersizer S. Detector for the Mastersizer X. 42 element composite solid state detector array - optimised for light scattering measurement, 1 centre detector, 2 alignment detectors, 2 backscatter detectors and 1 laser monitor. 31 element solid state detector array - optimised for light scattering measurement, 1 centre detector. G E T T I N G S T A R T E D Page A.3

149 APPENDIX A G e t t i n g S t a r t e d Detector electronics. 48, (31 for the Mastersizer X) amplifier parallel sample/hold construction, A/D conversion and on board digital storage. Sampling time 10µs for all 48 detectors of the Mastersizer S, and the 31 detectors for the Mastersizer X. Read in time to computer approximately 2ms. Sampling from internal/external trigger source. On board storage for 100 experiments. Digital I/O interface. 12 output, 16 input lines. Power requirements. Dimensions. Weights. 110/240V, 50/60Hz, 1200VA Standard Mastersizer 1200(L) x 335(H) x 290mm (W). Long bench Mastersizer 1853(L) x 335(H) x 290mm (W). Standard Mastersizer optical unit - 47 Kg. Long bench Mastersizer optical unit - 66 Kg. Computer requirements (minimum) Description. Data Capacities. Keyboard. Mouse. Ports. IBM-PC/AT compatible 486DX/33 or SX with Overdrive chip fitted (minimum). 4 Mbytes total RAM Memory, (minimum). 60 Mbyte (minimum) integral hard drive, (7.1 Mbytes required for Mastersizer software). 3.5" high density floppy disc drive. 102 key standard layout with 12 function keys. Microsoft Windows compatible. If a serial mouse is used note that the Mastersizer software, by default, expects the instrument to be connected to the COM 1 port. 1 serial port (COM 1) for use with the Mastersizer. A second serial port is required if you need to use a serial mouse or to control the Mastersizer and software by a remote computer. Parallel port for for a printer. Page A.4 MAN 0101

150 APPENDIX A Screen. Printer. Software. Enhanced VGA monitor supporting a resolution of 800 x 600 or greater is recommended. (The Malvern software is compatible with VGA resolution.) High resolution printer - 300dpi or greater. Microsoft Windows compatible. Laser or Bubble / Ink Jet type preferred. Colour printer is optional. MS-DOS Disc Operating System - all commands for; configuration of system, peripherals, disc management and batch operation capabilities. Version 5.0 or later required. Microsoft Windows A graphical interface software that allows control of the computer and data using simple visual metaphors. Version 3.1 or later, running in enhanced mode is required. Mastersizer software All files needed to operate Mastersizer, presented as an integrated suite with installation procedures. All Mastersizer files are contained in one directory named by the user, further sub-directories being automatically created. Utilities Presentation generator. The Malvern instruments warranty over the computer configuration only extends to those supplied by Malvern Instruments. Users should be aware that not all hardware sold as Microsoft Windows compatible is fully so. If you wish to operate your own configuration it should be fully tested before purchase. Malvern Instruments does not provide any warranty of software performance on user selected computer configurations. Mastersizer programme specification Loading Fully automatic with optional self starting of preprogrammed activities. Copying Copying restricted to end user use only. Passing on to others contravenes the software license. Configuration User tells system the optical configuration which is used to scale results correctly. G E T T I N G S T A R T E D Page A.5

151 APPENDIX A G e t t i n g S t a r t e d After use the system writes the configuration to disc and on subsequent use will automatically configure the Mastersizer to this last used mode. Recall also includes last data, results, programmes, key functions, etc. Easy mode Measurements made using buttons to select from a limited range of operations. These allow safe step by step operations to perform the measurement. User intervention is minimised. Guidance and help are given using; menus, advice and error messages during execution. Menu mode The system is operated by a selection of menu and sub-menu choices which may be made using the mouse or from the keyboard. Many sub-menu items which are frequently used may be selected by single key (accelerator) operations. Programme Mode Measurements are made using a command language (Sizer BASIC). These programmes may be stored and recalled from disc, automatically or manually run and allow fully automatic operations with little or no user interaction. Help features There is an extensive on-line help system available. Software Revision Level Malvern is engaged in a continuing programme of development, both in measurement capabilities and software features. Thus, during the lifetime of a product a number of software versions will exist, in general increasing in capability as they become more current. In general users of older versions will be able to purchase updates to these later versions if they are significant. Seek advice regarding costs from your local representative. Page A.6 MAN 0101

152 Chemical compatibility A P P E N D I X B

153

154 APPENDIX B Introduction The Mastersizer and its accessories have be manufactured from materials that are considered to give the widest protection from chemical attack. However, it is important to check that any sample or dispersant you may use is chemically compatible with the materials that they will come in contact with the system. This appendix will list all materials that come in contact with the sample and dispersant in the normal operation of the optical unit only. The sample and dispersant mostly come in contact with the sample accessories and the cells. See the accessory manuals of the accessories you have to check for chemical compatibility. Components in contact with sample and dispersant Wet sample measurements Component Location Materials Cell pipe connectors. Sample area cover. Stainless steel. Dry sample measurements Component Location Materials Sample area cover. External covers. Two-pack polyester paint. When using the Free Fall Dry powder Feeder it is possible to spill sample onto the covers. This should be avoided at all times. All spillages should be cleaned up immediately. G E T T I N G S T A R T E D Page B.1

155 APPENDIX B G e t t i n g S t a r t e d Spray measurements Component Location Materials Sample area Internal surfaces. Glass (lenses). Anodised aluminum. Two-pack polyester paint. Stainless steel. All spray measurements should be extracted to the outside of the building. However, some material may settle out onto the surfaces of the sample area. If this happens the area should be cleaned immediately. As an additional caution the paint finish of the external covers may be permanently damaged if samples or dispersants are spilt onto them. Any spillage must be scrupulously cleaned up immediately. Remember to check the chemical compatibility of your sample accessories before using a new sample and dispersant. Page B.2 MAN 0101

156 Remote interlock A P P E N D I X C

157

158 APPENDIX C Remote interlock The Mastersizer does not require an external interlock switch to comply with CDRH or EC laser safety regulations. However, some company safety regulations may require the room in which the Mastersizer is installed to be protected so that if the door to the room is opened then the laser in the optical unit is disabled. The Mastersizer allows you to do this by using the Remote connector socket on the transmitter end panel. This socket is shown in the diagram below. 1 ILL 3211 If no remote interlock is to be used then the connector is fitted with a shorting plug that will enable the laser to be switched on. It should be noted that the continual interruption of the power supply to the laser will reduce the life of the laser. To solve this problem an interlock switch system similar to the circuit diagram below is recommended. In this system there are two switches. The first is a normal interlock switch that is attached to the door of the room that will disable the laser when the door is opened. The second switch is a spring return type manual override switch that allows the user of the Mastersizer to keep the laser power on if they know that someone is going to enter the room. Using this configuration will reduce the number of times the laser is switched off by only disabling the laser when someone unexpectedly enters the room. The circuit is connected to the remote socket using a standard 3 pin DIN plug. G E T T I N G S T A R T E D Page C.1

159 APPENDIX C G e t t i n g S t a r t e d Note. The second switch must be of the spring return type that will automatically return the switch to the open position when the switch is released. INTERLOCK REMOTE L OFF/ V ILL 3630 Page C.2 MAN 0101

160 Estimating the absorption A P P E N D I X D

161

162 APPENDIX D Introduction When choosing the presentation for an analysis you will be required to enter a value for the imaginary refractive index (this is effectively the absorption) of the sample you are measuring. This can be difficult as the value has to be calculated by performing an experiment. However, in most cases the value can be guessed with very little effect on the result. In practice you will probably only use two values; if the sample in transparent (glass beads for example) then there will be no absorption so the value will be 0 (A on the grid), otherwise use 0.1 (H on the grid) as the absorption value. If you feel you need a more accurate value then it can be estimated by following the procedure below. Estimating the absorption using concentration measurements The following technique may be useful in estimating the absorption in certain cases. For a given measurement, the volume concentration is calculated using the equation:- k C = VQ i i d i where k is a constant (for fixed beam length and obscuration), V i and Q i are the relative volume concentration and extinction efficiency for particles of diameter d i. Q i is sensitive to the optical properties and so, also, will be the concentration. The technique then is first to determine the refractive indices of the particle and medium either from tabulated values or by direct measurement using a refractometer. A sample of known concentration is then prepared by mixing weighed amounts of the materials and a measurement made. The data is analysed using a range of presentations for the correct particle and medium refractive indices and a range of absorptions. The presentation which gives the closest agreement with the known volume concentration is then used as a good approximation to the correct absorption value. This technique has been used successfully with oil/water emulsions. It should be noted that, a good estimate of the real refractive indices is necessary and the beam length must be correctly entered (using the Setup - Hardware dialogue box), therefore the method is difficult to apply with spray measurements. G E T T I N G S T A R T E D Page D.1

163 APPENDIX D G e t t i n g S t a r t e d As an example consider the measurements shown below. A sample of material was suspended in water at a volume concentration of %. The differential refractive index is low and the size around 1µm so that presentation is important. The analysis was performed with presentations GAD, GDD, GFD and GHD. A plot of the log of reported volume concentration against absorption gives:- 1 Volume Concentration % GAD GDD GFD GHD Particle Imaginary Refractive Index ILL 1885 The horizontal line at 0.032% indicates that the closest approximation to the presentation is GFD with absorption Presentation Absorption Volume Concentration Residual GAD % 0.099% GDD % 0.119% GFD % 0.049% GHD % 0.531% The table shows that, in this case, the volume concentration match is a much more sensitive indicator of the absorption than the residual. Page D.2 MAN 0101

164 Advice for continuous sprays A P P E N D I X E

165

166 APPENDIX E Introduction The measurement of a continuous stable spray is the simplest that can be made with your instrument, requiring no essential extra accessories. Malvern offer an Aerosol Mounting Unit which you may find useful for repeatably positioning the nozzles and directing the spray. Arrange for the spray to be extracted Sprays are not contained within a cell and if there is nowhere for them to go after they have passed through the beam they can back circulate and possibly deposit out onto the optics. Remember therefore to consider where your spray goes after measurement and ensure that nothing prevents it. Avoid operating against walls or other equipment that prevent air circulation. Ideally arrange for an extraction air flow. Also consider any health risks when spraying hazardous materials. Use the correct optical configuration Because all normal sprays will occupy a long illuminated beam length it is not feasible to measure sprays using the 300RF lens and the Mastersizer S or the 45mm lens on the Mastersizer X. In addition, the short lens cut-off distance of the 300mm range restricts the usefulness of this range for sprays. The most suitable range is the 1000mm range (long bench users only) but the 300mm range may also be used if you pay attention to the possibility of the large angle scattering being cut-off (vignetting) by the lens aperture. Positioning the spray nozzle A spray invariably expands in extent as it travels away from the nozzle. If no evaporation occurs then this means that the concentration of particles that will lie at any time in the Mastersizer analyser beam will reduce as the distance from beam to nozzle increases. Close to the nozzle there will be a limit caused by the concentration being too high for accurate measurement. Downstream a limit will also occur where the spray concentration has become so low as not to be reliably detectable. Between these extremes an acceptable range of measurements can be made. In some types of spray the droplets do not reach a stable size until some distance away from the nozzle. Close to the nozzle the liquid may be in the form of G E T T I N G S T A R T E D Page E.1

167 APPENDIX E G e t t i n g S t a r t e d ligaments that will later divide into stable droplets. Thus the limiting minimum distance may not be set by concentration considerations alone. In other sprays the droplets themselves may be volatile and evaporate rapidly causing size distributions that will change with distance from the nozzle. For all of the above reasons it is important to choose carefully the distance between the nozzle and the analyser beam. Having set a suitable distance satisfied by measurements, continue to use this configuration every time. It is most common for measurements to be made with the analyser beam intersecting the centre of the expanding spray cone. The result reported is the average size distribution in the volume of spray in the beam. By moving the beam off the spray axis it is possible to obtain the average size distribution in a different part of the spray. By this means it is possible to probe the spatial variation of size distribution and hence obtain further diagnostic information about the nozzle characteristics. Don t spray the optical unit Care is required to avoid the spray settling on the lenses. The droplets formed will scatter light and distort the size distribution accordingly. Ensure the spray is stable during measurement Variations or inconsistent spray performance during the measurement can lead to fluctuating results. Try to ensure that the spray conditions are stable and if fluctuations are inherent remember to increase the measurement interval so that averaging increases the result stability. If you wish to probe time variations in the size distributions then you must use the Spray Synchroniser accessory which allow accurate time resolution of the size measurement. For advice on making pulsed spray measurements please see Spray Measurements in the Software Reference manual. Page E.2 MAN 0101

168 Malvern addresses A P P E N D I X F

169

170 APPENDIX F Malvern subsidiaries If you purchased your Malvern Mastersizer from an agent for Malvern Instruments Ltd. products please contact them for servicing and sales information. If you purchased your Malvern Mastersizer from Malvern Instruments direct please use the following information to contact us. Head Office: Malvern Instruments Limited Spring Lane South Malvern Worc s WR14 1AT Tel: +44 (0) Fax: +44 (0) Malvern Instruments Inc 10 Southville Road Southborough MA U.S.A. Tel: Fax: Malvern Instruments SA Parc Club De L Université 30 Rue Jean Rostand Orsay Cedex France Tel: +33 (1) Fax: + 33 (1) Malvern Instruments GmbH Rigipstraße Herrenberg Germany Tel: +49 (0) Fax: +49 (0) G E T T I N G S T A R T E D Page F.1

171 APPENDIX F G e t t i n g S t a r t e d Malvern Instruments (Asia Pacific) 38 Jalan Bangkung Bukit Bandaraya Kuala Lumpur Malaysia Tel: +60 (0) Fax: +60 (0) Malvern Instruments Nordic AB Vallongatan Uppsala Sweden Tel: +46 (0) Fax: +46 (0) Page F.2 MAN 0101

172 Regulatory compliance statements A P P E N D I X G

173

174 APPENDIX G Statement of LVD compliance The CE badge on this product signifies conformance to European Commission Directive 72/23/EEC the Low-Voltage Directive as amended by Directive 93/68/EEC the CE Marking Directive. The directive has been satisfied for Malvern equipment by applying BS EN :1993 Safety requirements for electrical equipment for measurement, control, and laboratory use Part 1 - General requirements. Statement of EMC performance for the Mastersizer S The CE-badge on this product signifies conformance with the protection requirements of the European EMC directive, (89/336/EEC). The following statement of EMC performance refers to the Mastersizer S system as defined below operating under the following test conditions. Equipment under test Equipment Mastersizer S Model MSS Support equipment: NEC PowerMate 386/33i VDU Kbd Mouse PM APC-H5340 APC-HH122 M\N M-SE9-6MD Test conditions The Mastersizer S is a particle size measurement instrument, controlled and operated from a computer. The particles are presented in a suitable medium within a test cell through which a laser beam is focused. The diffraction pattern produced by the particles is measured and from the result the size of the particles is calculated. G E T T I N G S T A R T E D Page G.1

175 APPENDIX G G e t t i n g S t a r t e d During emission tests the equipment was under control of a Mastersizer S Version 2.11 Software Automated Sequence. This repeatedly measured a known sample. For immunity tests the operator checked that the measurement was within the determined experimental error, and if outside this pre-set tolerance flagged or noted an error. The susceptibility pass/fail criteria was that the equipment repeats the measurement within the norm of experimental error. EMC performance The equipment under test, when subjected to the following tests was found to be compliant. Complies with EN (1995), generic emission standard (industrial environments). Complies with EN55022 (1995), class B, radiated and conducted emissions. Complies with EN (1995), generic immunity standard (industrial environments). Complies with EN (1995), Electrostatic discharge, to severity level 4, with performance criteria A, ie. no loss of function or performance. Complies with DDENV50140, (1994), Radiated electromagnetic field, to 10V/m, with performance criteria A, ie. no loss of function or performance. Complies with DDENV50204, (1995), Radiated electromagnetic field, to 10V/m, with performance criteria A, ie. no loss of function or performance. Complies with EN (1995), Fast transient burst, to severity level 4 with performance criteria A, ie. no loss of function or performance. Complies with DDENV54141 (1994), Conducted RF susceptibility, to 10V with performance criteria A, ie. no loss of function or performance. Page G.2 M A N

176 APPENDIX G Statement of EMC performance for the Mastersizer X The CE-badge on this product signifies conformance with the protection requirements of the European EMC directive, (89/336/EEC). The following statement of EMC performance refers to the Mastersizer X system as defined below operating under the following test conditions. Equipment under test Equipment Model Mastersizer X MSX build version Feb 93 Support equipment: NEC PowerMate 386/33i VDU Kbd Mouse PM UB JC-1521HMP-EE 2YT01803A APC-H M M\N M-5E9-6MD A Test conditions The equipment under test measures the size of particles by means of laser diffraction. An optical reticle was placed in the path of the beam to simulate a given particle size. The computer is polled to the Mastersizer, and calculated the particle size result. The computer program was instructed to signal an alarm condition if the measured particle size fell outside the acceptability band. This represented the EUT failure criteria. This also represented the equipment under test activity for emissions. EMC performance The equipment under test, when subjected to the following tests was found to be compliant. Complies with BS EN (1994), generic emission standard (industrial environments). G E T T I N G S T A R T E D Page G.3

177 APPENDIX G G e t t i n g S t a r t e d Complies with BS EN55022 (1995), class B, radiated and conducted emissions. Complies with BS EN (1995), generic immunity standard (industrial environments). Complies with BS EN (1995), Electrostatic discharge, to severity level 4, using 8kV contact discharge and 15kV air discharge, with performance criteria 1, i.e. normal performance within specified limits, i.e. generic performance criteria A Complies with DDENV50140, (1994), Immunity to radiated electromagnetic energy to severity level 3 (10V/m 1kHz 80% AM 80MHz - 1GHz and 200Hz 1000PM at 900Hz) with performance criteria 1 i.e. normal performance within performance criteria 1. i.e. generic performance criteria A. Complies with BS ENV , immunity to electrical fast transient/bursts, to severity level 4 using 2kV on signal lines and 4kV on power supplies, with performance criteria 1, i.e. normal performance within specified limits, i.e. exceeds specified requirements to generic performance criteria A. Complies with BS ENV50141 (1995), Immunity to conducted RF disturbances to severity level (10Vrms 1KHz 80% AM 150KHz - 80MHz) with performance criteria 1 i.e. normal performance within specified limits, i.e. generic performance criteria A. Page G.4 M A N

178 Index

179

180 INDEX A Abort connector 2-9 Access to the instrument 1-2 Malvern personnel 1-2 Operator 1-2 Supervisor 1-2 Accessory panels 2-6 Adding the sample 4-11 Admixtures 9-5 Align button 4-10 Alignment 3-4, 4-10 Intelligent Align 4-10 Analysis Analysis model 3-6 Calculating the result 3-7, 5-8 Choosing the correct analysis mode 5-1 Compressed range 3-6 Monomodal 3-6, 5-1 Multimodal 5-1 Presentation 3-6 Selecting 5-2 Sequence 8-2 Very polydisperse 3-6, 5-1 Automated Sample Dispersion Unit 1-3, 2-1 Aux. Comms connector 2-9 B Back scatter connector 2-7 Background 3-5 Background measurement 4-11 Bitmap Editor 2-10 Blending results 10-8 Bubbles 9-3 Button bar 2-12 Buttons Align button 4-10 Background 4-11 Document 4-8 Inspect button 4-13 Next 4-9 Previous 4-9 Print 6-4 Setup sequence 8-1 Start/stop 4-9 C Calculating the result 3-7 Cells 2-6 Air 2-6 Flow 2-6 Pipe connectors 2-6 Stirred 2-6 Choosing a presentation 5-3 Cleaning the beam expander 11-7 Cleaning the cell windows 11-4 Cleaning the covers 11-3 Cleaning the range lenses 11-6 Colours Table 6-3 Compressed range 3-6 Computer 2-2 Computer Comms connector 2-8 Cursors Kill 10-4 Help jump 2-19 Query 2-14 Splitter bar 2-15 Cut off 4-3, 4-5 D Derived distribution parameters 7-3 Detector 3-2 Digital I/O connector 2-9 Dispersant 9-3 Dispersion method 4-5 Document button 4-8 Document the measurement 3-5, 4-8 Dry sample preparation 9-2 E Easy buttons SEE Button bar Easy mode 2-15 Equivalent spheres 7-2 G E T T I N G S T A R T E D Page 1

181 INDEX G e t t i n g S t a r t e d Estimating the absorption D-1 Extending the result 10-6 F Finding your way around the screen 2-11 Flow cell 1-3 Fonts Graph fonts 6-7 Table fonts 6-7 Fraunhofer 3-1 Frequency curve 3-3, 7-5 Fuse holder 2-3 Fuses 11-2 G Graph dialogue 6-2 Graph fonts 6-7 Graph pane 2-14 Graphs 7-4 H Hardware setup 4-7 Help 2-16 F1 Function key 2-17 Help jump cursor 2-19 Help menu 2-17 Help window 2-17 Jumps and Popups 2-18 On-line help 2-16 Status line 2-19 Histograms 3-3, 7-5 I Identifying a range lens 4-3 In-band 3-3 Inspect 3-5 Inspect button 4-13 Intelligent Align 4-10 Interlock connector 2-3 K Kill cursors 10-4 Killing channels 10-1 L Laser interlock connector 2-7 Laser interlock switch 2-7 Laser power indicator 2-4 Lens Changing 4-7 Cut off 4-5 SEE Range lens Live display 4-10 Long bench Mastersizers 2-9 LV out connector 2-3 M Maintenance Cleaning the beam expander 11-7 Cleaning the cell windows 11-4 Cleaning the covers 11-3 Cleaning the range lenses 11-6 Fuses 11-2 Replacing the sample tubing 11-1 Malvern personnel 1-2 Malvern presentation grid 5-4 Mastersizer program group 2-10 Bitmap Editor 2-10 Mastersizer program icon 2-10 Presentation generator 2-10 Measure windows 4-8 Measurement 3-2 Add the sample 3-5 Align the optics 3-4, 4-10 Background 3-5, 4-6, 4-11 Inspect 3-5, 4-12 Instrument preparation 4-6 Making a measurement 3-4 Measure 3-5, 4-13 Measure windows 4-8 Obscuration 3-5, 4-12 Setup the hardware 4-7 Menu bar 2-11 Menu commands 1-5 Menu mode 2-15 Mie theory 3-1 Modes of operation 2-15 Page 2 MAN 0101

182 INDEX Easy mode 2-15 Menu mode 2-15 Program mode 2-16 Modifying results 10-1 Blending results 10-8 Extending the result 10-6 Kill cursors 10-4 Killing channels 10-1 Multiple modifications 10-9 Shape correction 10-4 Transforming result type 10-7 Tromp curve analysis 10-9 Monomodal model 3-6, 5-1 Multimodal mode 3-6, 5-1 N Next 4-9 O Obscuration 3-5, 4-12 Operator 1-2 Optical unit 2-1, 2-2 Optical unit power switch 2-4 Other reading 1-7 Oversize plot 3-3, 7-5 P Polydisperse model 3-6, 5-1 Power input socket 2-3 Power switch 2-4 Presentation 3-2, 3-6 3$$ $$A 5-8 3$$D 5-8 Choosing 5-3 Fraunhofer (3$$D) 3-7 Grid 5-3 Methods of selecting 5-5 Reference Reticle (3$$1) 3-7 Special 5-8 Standard - Dry (3RHA) 3-7 Standard - Wet (3OHD) 3-7 Presentation grid 5-4 Previous button 4-9 Printing 6-4 Graph 6-10 Installing a printer 6-8 Print button 6-4 Report 6-10 Table 6-10 Understanding printing 6-6 Window 6-10 Program mode 2-16 Q Query Cursor 2-14 R Range lens 2-5 SEE Cut off SEE Choosing SEE Identifying Receiver 2-2, 2-7 Abort connector 2-9 Aux. Comms 2-9 Computer Comms 2-8 Detector 2-8 Digital I/O 2-9 Exp. trigger 2-9 L.V. In 2-9 Sweep trigger 2-9 Records 3-8 Remote connector 2-3, C-1 Replacing the sample tubing 11-1 Reports 6-3, 7-5 Representative sampling 9-1 Residual 3-7, 5-9 Riffler 9-2 Run number 3-8 S Sample area 2-2, 2-4 Back scatter connector 2-7 Beam expander 2-5 Cell pipe connectors 2-6 Laser interlock connector 2-7 Laser interlock switch 2-7 Range lens 2-5 G E T T I N G S T A R T E D Page 3

183 INDEX G e t t i n g S t a r t e d Removable accessory panels 2-6 Sample area cover 2-5 Sample cell 2-6 Sample area cover 2-5 Sample cell 2-6 Sample file 3-8 Sample preparation 4-2, 9-1 Riffler 9-2 Bubbles 9-3, 9-7 Dispersant 9-3 Dry samples 9-2 Slurries 9-6 Ultrasonics 9-6 Wet samples 9-3 Sample preparation accessory 2-1 Saving the result 3-8 Scattering pattern 3-2 Sequence 8-1 Setup sequence button. 8-1 Setup measurement 3-4 Shape correction 10-4 Slurry 4-12, 9-6 Software 2-10 Software screen 2-9 Button bar 2-12 Graph pane 2-14 Menu bar 2-11 Splitter bar 2-15 Status bar 2-15 Table pane 2-14 Title bar 2-11 Splitter bar 2-15 Splitter bar cursor 2-15 Start/stop buttons 4-9 Status bar 2-15 Surfactants and admixtures 9-5 Sweep trigger connector 2-9 Sweeps 3-2 Systems covered by this manual 1-1 T Table fonts 6-7 Table pane 2-14 Tables 7-4 Theory 3-1 Derived distribution parameters 7-3 Equivalent spheres 7-2 Fraunhofer 3-1 Mie theory 3-1 Volume based results 7-1 Transforming result type 10-7 Transmitter 2-2 Fuse holder 2-3 Interlock connector 2-3 Laser power indicator 2-4 Laser power key 2-4 LV out connector 2-3 Optical unit power switch 2-4 Power input socket 2-3 Remote connector 2-3 Tromp curve analysis 10-9 Typical system 2-1 U Ultrasonics 9-6 Undersize plot 3-3, 7-5 Unstable concentrations 9-7 V Very polydisperse model 3-6, 5-1 Viewing the result 3-8 Views 6-1 Graph 6-2 Overview 6-4 Vignetting 4-5 Volume based results 7-1 W Wet sample considerations 9-3 Where to find information 1-5 Windows terms 1-3 Page 4 MAN 0101