ECM Solutions for Oil / Gas / Refinery Industries ECM ECO Monitoring, a.s. Bratislava (Slovak Republic) is focal company of the ECM Group consisting from a network of subsidiaries and offices to offer an optimal technical and comercial support on field of monitoring instrumentation of gases, liquids and particles. ECM is offering for Oil / Gas / Refinery Industries a broad range of applications: Process monitoring: Paramagnetic, zirconia, electrochemical and optical oxygen analyzers to monitor both percent and trace level concentrations in different gas mixtures O2 / CO analyzers to control combustion processes also in explosive areas IR / VIS / UV analyzers for monitoring of different gases and liquids Sulphure monitoring content of gases and liquids Physical properties like RVP, viscosity, flash point, cloud point, distillation point, freezing point, color, turbidity, etc. NIR, FTIR and Raman analyzers for blending and monitoring of gasoline, diesel, aromates, and crude oil features Claus process feed gas, tail gas, CEMS Moisture of different gases, liquidy and solids Process gas chromatographs with up to 6 furnaces with individual dynamic programing and choice of different detectors Fast Mass spectrometers Hydrocarbons in process waters Hydrocarbon tank draining systems Digital thermography for safe operation of hydrocrack furnaces Monitoring of ethylene plant furnaces Moisture independent mass flow monitoring of different gas mixtures Wobbe index and heat value of different waste gas mixtures Flare gas monitoring
Monitoring of product pipelines Natural gas composition monitoring Flare ignitors Denox and desuphurisation monitoring for waste oil combustion boilers Water quality monitoring Oil in water analysis Circulating water monitoring Hydrocarbons on water surface Water treatment plant monitoring Influent / Efluent monitoring Level and flow monitoring Ultrasonic and radar level / flow monitoring Non invansive level monitoring of liquids in tanks Mass flow monitoring of flare and waste gas monitoring with no influence of gas moisture fluctuations Clamp on monitoring for liquids and gases Environmental monitoring CEMS systems available also for explosive areas Ambient air monitoring Working area monitoring Others Stationary and portable monitors of toxic and flamable gases Calibrators and bump testers with no need of external calibration gases Breathing protection testers Catalytic additives to clean combustion chambers from deposits and protect against high and low temperature corrosions Optimation of power generation Denox control, acid dew point, oxygen, CO and particle monitoring
Blending Process Analysis These systems are to control gasoline, diesel or aromate blending processes in oil refineries. The system is consisting from sampling systems with absorption cuvettes of the particulate parts of the process. The sampling systems provide necessary filtration, pressure compensation and sample circulation as appropriate. The sampling cuvettes are connected by optical cables to the analytic system which is based on optical absorption with possibility to apply chromatographic instruments as well.
Claus Process For Claus process control is essential to monitor the feed gas and tail gas. Especially the tail gas monitoring is difficult because of sampling system plugging by sulphur. ECM is providing compact low maintenance light reliability systems for both applications. H2S and SO monitoring at high sulfur background UV spectrometer allows a broad dynamic range eliminating interferences Housing allowing installation without protective shelters New intake probe design avoiding sulfur to enter the analytical part preventing plugging problems Service interval is 30 days!
Calorific Value Analyzers Calorific value analysers are to monitor natural gas, petrochemical waste gases, coke gas, blast furnace top gas, biogas... ECM is offering several solutions: Miniature gas chromatographs for analysis of gas compositions and caloric value of natural gas. An accurate instrument optimized for any natural gas related application. Catalytic oxidation based analyzers to monitor Wobbe index or calorific value of flammable and even on flammable gases.
Combustion Control Systems The Promecon systems allow significant optimization of the thermal processes such as coal fired boilers, smelter processes, cement kilns and others. Using innovative technologies emissions are reduced, efficiency and availability of plants are entranced. The Promecon optimization system is utilizing several innovative sensor products: Cross correlation based combustion air flow sensors working reliably in harshest conditions for up to 40m/s flow speed and up to 1100 C temperature. - No calibration needed - No drift, no cleaning - Not affected by high dust SIL2 available coal mass flow/velocity/particle size measurement - Long life ceramic sensors 50-10 000 g/m3 concentration 0-100 t/hr mass flow 10-60 m/s velocity 30-60 um particle size - Different probe length, ATEX Fast responding temperature sensor on mill classifiers without abrasion. Online unburned carbon measurement. This is the World most sold fly ash analyzer. - Lab accuracy in process 0-20% carbon in fly ash 2-10 minutes measuring cycle
System Application for Boiler Optimization PROMECON is a total solution provider for Boiler optimization. Patented, unique online measurement systems for PF/ Biomass, PA, SA, OFA, particle size distribution, carbon in fly ash and other parameters. Evaluation of pulverizer, coal pipes, air ducts, boiler, APH. Improved control concepts for increased load gradient, low load operation, multifuel burning etc. Our references are our (PROMECON) references. Installed basis > 2000 sensors. All designed and made in Germany. Tuning through measurement and control (APC). We handle complete projects, CFD, modification of ductwork, trimming dampers, optimization. Typical projects: Plant assessment, Efficiency testing, Boiler optimization, Advanced process control. Field of projects: Pulverizer, coal/air distribution, combustion, fluegas.
Oil in water analyzers Since oil in water means a broad range of water pollutant in terms of chemical composition, concentration, phase and other characteristics, so are also the appropriate analytic methods. ECM is offering application specific fluorescent, chromatographic, extractive and spectrometric analyzers to monitor all kinds of hydrocarbons in water in broad range of concentrations. Typical applications are: Waste water systems in oil / gas industry Chemistry and petrochemistry Drinking water treatment Steel industry and metallurgy Truck / train washing yards Airports Oil in condensate and cooling water Power generation
Oxygen monitoring Flue gas Tuneable laser O2 / CO analyzers for large boilers Zirconia and catalytic CO Main adventages: Yearly calibration interval Same analyser for 150 C - 1500 C temperature range Combination of laser and Zirconia probes allows safe detection of areas with excess or lack of oxygen in combustion process Our laser monitors allow to use air purge instead of usual nitrogen to keep the optics clean
Process gases Broad range of paramagnetic, zirconia, optical or electrochemical analyzers from trace concentrations up to oxygen purity monitoring around 100% O2 concentration. The main applications are: Clean industrial gas production Oxigen content in different process gas mixtures Inertization processes Working area safety Process Gas Monitoring / Liquid Monitoring Systems Examples of process monitoring applications are: O2 monitoring on different levels and in different media CO, CH4, CO2 monitoring in different gas mixtures He, H2, N2, Ar purity of industrial gases Medical gas purity Oil / gas industry monitoring applications Heat value and Wobbe index Claus process feed and tail gas monitoring TS and H2S monitoring in different media Sulphure in fuel Process chromatography Water in solvents Moisture monitoring in different media Semiconductor industry gas / liquid monitoring PVC plant gas / liquid monitoring Complex monitoring solutions for chlorine chemistry Complex monitoring solutions for nitrogen chemistry Air separation monitoring ECM is providing analytic solutions for on-line monitoring of process gases for different applications: Combustion process control Fast response O 2 and CO monitoring systems
Industrial analysers for chemical and petrochemical applications NDIR analysers for SO2, H2S, CO, CO2, NH3, HCl, CH4 and many other gases H 2 S and Sulphure analysers for gases and gasoline Paramagnetic oxygen analysers for different media Industrial analysers for pharmaceutical industry semiconductor industry and clean gas manufacturers O 2, SO 2, NO, CO, CO 2, CH 4 multicomponent analysers Multicomponent FTIR analysers for broad range of compounds Accurate oxygen analysers Physical property: Dew point, Cloud point, Flash point, Distilation point, etc. analyzers Hydrogen analyzers
Biogas monitoring CO, CH4, CO2, H2S analytic systems Analysers for cement kiln control CO,CO 2, O 2, NO monitoring for high temperature and dusty atmosphere Claus process tail gas monitoring H 2 S/SO 2 monitoring in the high sulphur content Claus process tail gas atmosphere Analysers for food industry: O2, CO2 analysers for package gases CO 2 purity analysers for beverage manufactures Process gas chromatographs The instruments are to monitor different gaseous compounds, which can be not measured by sampler methods Analysers for clean gas manufacturers Analysers for cleaners and trace level monitoring of Ar 2, O2, N2 and other gases
Process Gas Chromatographs The next generation process gas chromatograph, the FXi Series5 system was developed from a heritage of highly reliable and field proven systems. The FXi Series5 system continuously analyzes and reports component concentrations and physical properties of process gas streams in a variety of applications in the natural gas, refining, petrochemical, chemical and pharmaceutical industries. LAMS Windows based FXi software operated by a touchscreen colorgraphical user interface. Seamless connectivity with DCS and LAN systems through Modbus, OPC, Ethernet and analog protocols. Large, easy to read display of real-time chromatograms with zoom and overlay features eliminates the need for strip chart recorders. Versatile detector and column options can beintegrated with the FXi system to provide application flexibility. Detector options include Thermal Conductivity (TCD), FlameIonization (FID), Flame Photometric (FPD) and Helium Ionization (HID).Column options include capillary, micro-packed, and packed columns. Highly stable, field proven and easily maintained analyzer oven provides outstanding chromatographic performance with a high level of uptime. New Carrier Gas Flow Control Regulator System or Electronic Pressure Regulator System are available as options. Foxboro 931A, 931C & 931D Upgrade Kits Enhance the useability of your existing Foxboro asset by taking a close look at our economical upgrade alternatives. Field installed, the kits give you the benefits of the most current technology for a fraction of the cost of a full system replacement. Easy to use LAMS Windows based software operated by touchscreen Real-time chromatograms Flexible communications Advanced analysis capability
Continuous Emission Monitoring Systems (CEMS) For continuous emission monitoring systems usually monitored compounds are: SO₂ HCl Particles H₂S NOx HF Flow TRS CO NH₃ Pressure CO₂ CxHy O₂ Temperature ECM is providing stack gas monitoring systems based on all currently available architectures: Straight extraction Dilution In-situ Instrumentation offered for European clients is QAL1 certified. The gas monitoring instrumentation is based on proven techniques: NDIR UV absorption UV fluorescence Chemiluminiscence FTIR Tuneable laser diodes FID The QAL1 certified particle monitoring instrumentation is based on opacity, light scattering, tribo, or electrodynamic methods. Flow monitors are based on following methods: Ultrasonic Anubaric Thermal conductivity The ECM Data systems are fulfilling all legislative requirements including the QAL3 support defined in EN 14181 standard.
Sulfur monitoring Sulfur analyzers to monitor concentrations from trace levels up to high percent concentrations. The main applications are oil / gas industry, food and beverage industry, Claus process, paper / pulp industry and waste water treatment. In Oil / Gas industry the main applications are: H2S in natural gas Sulfur content of diesel and gasoline Natural gas odoration Flare gas monitoring Stack gas emission monitoring The instrumentation is based on UV spectrometry, tuneable laser diode analysers, chromatography or lead acetate based monitors.
Toxic and combustible gas detectors Broad range of stationary and portable toxic and flammable gas detectors. The instruments can be provided with a wireless transmission with a several kilometres range. Instrumentation allowing to set up in few seconds an accident site. The emergency team control has a permanent information about the risks the members are exposed to. Stationary systems can be installed in few minutes without any need of obstaculous cable connections. Higher category of the instrumentation allows reliable detection of almost all kinds of hazardous gases. Personal monitors Site survey instrumentation Portable instruments
Fixed instruments Wireless infrastructure Software
Turbidity and colour monitors Monitoring instrumentation of opacity, particle content and colour of liquids. Water monitoring of solid contamination, turbidity and colour of drinking water, waste water, surface and industrial water including size categorisation of the particles. Monitoring of water colour, turbidity and organic pollution in parallel. Industrial liquids colour and turbidity analyzers of hydrocarbon mixtures and other industrial liquids in accordance to ASTM or other norms.
Water Quality Samplers
Flowmeters and level monitors Kurz provides flow meter products of outstanding quality and exceptional dependability that exceed the most challenging industry requirements. In dry or wet gas environments, Kurz flow meters define the industry standard for the highest repeatability, accuracy, and reliability. Applications that call for general information, exacting accuracy, or system protection rely on Kurz devices for real-time sensor and electronics diagnostics, and dependable temperature compensation. After more than 35 years of manufacturing flow monitoring equipment, Kurz continues its commitment to supplying innovative devices while encouraging the world to look at thermal mass devices as a cost-effective alternative to other flow measurement technologies. Thermal Flow Meters for Monitoring Dry and Wet Gas Environments Single-point insertion flow meter The Kurz Series 454FTB-WGF is the first thermal mass flow meter engineered specifically for wet gas, condensing gas, and biogas environments. The patentpending design processes the dry flow signal independent of the effects of moisture in the process gas stream, making it the ideal flow meter for digesters, landfills, animal feeding operations, wet stacks, and mining. The Kurz Series 454FTB is the premier single-point insertion thermal mass flow meter for industrial gas flow measurements. The 454FTB supports process temperatures from -40 C to 260 C and from -40 C to 500 C, process pressure ratings up to 300 PSIG, and a velocity range from 0 to 24,000 SFPM Multipoint Insertion Flow Meters K-BAR 2000B multipoint insertion flow meter uses up to four sensors for measurement redundancy and to ensure accuracy. Its rugged design withstands the high stress and high vibrations found in large industrial stacks and ducts that commonly have wide-ranging velocity and temperature profiles. The K-BAR 2000B supports process temperatures up to 260 C or up to 500 C. In-line flow meter The Series 534FTB The Kurz 534FTB is designed with built-in inlet and outlet piping educers/expanders to produce exceptional immunity to upstream and downstream flow disturbances caused by elbows, valves, and line size changes. The patented technology results in output with exceptional low end-to-end pressure drop and the fastest response to velocity and temperature changes in the industry. The Series 504FTB in-line flow meter is designed for applications where flow disturbances or line size changes are not an issue. The 504FTB is available in 10 models for inline sizes from ½ to 4 pipes. Portable flow meter The Model 2445 High-Temperature Portable Flow Meter is designed for very high temperatures (500 C) applications, such as coal-fired power plant stacks, and primary and secondary air ducts. The Model 2445 is available in five fixed lengths from 24 to 72 with a 3/4" diameter sensor support. The rugged all-welded construction and large size of the Model 2445 make it ideal for dirty and corrosive environments. It includes an all-metal display module, battery charger, carrying case, and several accessories. The Model 2444 Heavy Industrial Portable Flow Meter provides the flexibility for a wide
variety of field measurement applications because of multiple 16 sections that can connect up to 64.5 long. The Model 2444 works with high temperatures up to 200 C. It includes an all-metal display module, battery charger, carrying case, and several accessories. The Model 2443 Flow Meter is a small, rugged sensor designed for velocity and temperature traverses in small- to medium-sized pipes/ducts, such as in industrial ventilation systems. The 13" long probe shield can be reversed to extend the 3/8 sensor support. It includes an all-metal display module, battery charger, carrying case, and several accessories. The Model 2442 HVAC Portable Flow Meter is designed specifically for HVAC applications. The bendable gooseneck design and telescopic wand allows maximum flexibility in obtaining accurate traverse measurement in typically difficult location, such as ceilings, supply grates, and open areas. The wand reaches 47 when fully extended. It includes an all-metal display module, battery charger, carrying case, and several accessories. The Model 2441 Lab Grade Portable Flow Meter is excellent and well-suited for industrial hygiene and HVAC measurements. The dual-sting ceramic sensor is mounted in a ¼ diameter, 13 long sensor support with a shield/extender. The ceramic sensor provides a faster response time than the standard sensor. It includes an all-metal display module, battery charger, carrying case, and several accessories. The Series 490-IS incorporates Kurz sensor expertise into an inexpensive miniature thermal air velocity meter that you can take anywhere. The 490-IS is ideal for velocity measurements for EPA and OSHA emission regulations for a wide variety of vapor emission sources. The 490-IS is intrinsically safe. Mass flow computer The Series 155 Mass Flow Computer is available in five models, depending on the number of flow meters and sensors in your flow meter system. The Series 155 Mass Flow Computer integrates the functions of temperature and flow measurement, closed loop flow control, flow totalization, alarms, input/output calibration, and data acquisition for up to 22 sensors. Isokinetic sampling system Kurz offers a complete isokinetic sampling system to ensure true sample composition from stack flow monitoring and sample capture to sample flow control. The Kurz Emissions and Sampling System provides accurate sample collection for environmental, process, and nuclear applications. It eliminates under- or overreporting gas or particulate constituents. A wet stack option is available. The Isokinetic Sampling System includes: The KBAR-2000B multipoint insertion flow meter The Series 220 Isokinetic Sampling System A Kurz 504FTB or 534FTB in-line flow meter The Kurz 730 Rotary Ramp Valve provides fine control of the sample flow The Series 155 Mass Flow Computer
Special solutions are available for industrial sectors like: Coal power Incinerators Landfills Metal Nuclear Petrochemicals Pulp & Paper Wastewater Other flow meters based on ultrasonic, pressure difference, curiolis, magnetic induction, are also available. Level monitors based on all known principles: Ultrasonic Radar Capacity Floater
Catalyzer against boiler pollution Catalyst SP ECO SOTIN causes consumption reduction of coal and oil fuels between 3% and 8%. SOX, NOX, CO and ash emissions are reduced too Fuel combustion for the production of energy takes place according to the following chemical reaction Carbon + Oxygen = CO2 However, because the fuels used don t consist of pure carbons, some pollutants leave the hot zone area as unburned particles, thus slag settle on heating surfaces and dramatically reduces heat exchange and energy efficiency of whole process. By coal fuel are the most problematic particles of SO 2 and SO 3 meanwhile by oil fuel it is V 2 O 5. Heating surface before cleaning Cleaning process After cleaning Slag settled on heating surface causes corrosion of metallic parts. Low melting point makes slag a liquid, thus covering of surfaces is quick, efficient and constant. Chemical reactions of pollutants are consuming O 2 what in effect changes combustion process and drops efficiency even further.
How SP ECO works Two types of steel corrosion are found in boilers: Low temperature corrosion (acid corrosion) High temperature corrosion (vanadium corrosion) Reactions Reduction of negative effects of ash and slag is accomplished by the following reactions: a) SO3-bonding and SO3-collection: 2 KOH + SO 3 = K 2 SO 4 + H 2 O 2 KOH + SO 2 = K 2 SO 4 + H 2 The result is a considerable reduction in the concentration of SO 3. b) Bonding of vanadium oxides 2 KOH + V2O5 _ 2 KVO3 +H2O This reaction shows that V2O5 compounds are transformed to potassium vanadate salt. In the high temperature range potassium vanadate salt forms an enamel-like coating that serves as a protective film against corrosion. The main fireclay compounds are: Al2O3, SiO2, CaO and aluminium silicate. KOH (particularly in fluid form) can be melted with aluminium silicates without negative side-effects on the structure and consistency of the fireclay. Together with ash components, SP-ECO form eutectoids with high melting points. Thus it is not possible for agglomerates of ash and slag to form and attach to the heating surfaces. Existing agglomerates of ash and slag crumble under the effect of the catalyst and drop off. SP-ECO advantages SP-ECO changes chemical reactions with following results: Both SO 2 and SO 3 react to K 2 SO 4 with melting point of 1069 C, thus become solid without ability to accumulate on any surfaces. Existing deposits react to K 2 SO 4 with same results. It is not needed to increase temperature in boiler due to pollutants. SP-ECO is an oxidant and reactions driven by it consumes less of oxygen to let combustion be as effective as possible. SP-ECO limits creation of NO 2 and causes mainly NO, while created CO is converted to CO 2 with high efficient rate too. Since it is not needed to increase temperature as mentioned above some of polluting and corrosive reactions won t take place at all and unburned particles finish as solids in ash. In case of vanadium pollution/corrosion SP-ECO converts V 2 O 5 to KVO 3 (+ H 2 O) which doesn t accumulate any deposits and doesn t react with metal pipes.
SP-ECO has no side-effect on the structure and consistency of the fireclay Application direct injection into the combustion chamber forms a concentrated grayish white gas cloud which fills the entire interior of the boiler penetrates the flue gas deposits to form a eutectic system with different melting points the resulting thermal stresses crumble these deposits, which are then gradually stripped away after deposits have been eliminated, the pipeline system is directly exposed to SP ECO which prevents any new deposits and corrosion Ignites at 321 C Contains oxygen, therefore does not consume oxygen during combustion Consists of Potassium Nitrate + combustion materials Does not contain any aggressive chemicals or chlorides Does not damage the boiler or the walls of the boiler Is non explosive Is odourless UN number 1479 Class 5.l SP ECO SOTIN is injected directly into the combustion chamber every 6-8 hours. First dosage 40 days: 300g/t Continuous operation: 100 g/t No additional investment costs Manually dosed (small boilers) Or mobile injector connected to compressed- air supply (4 6 bar) Duration of in jection (max 60 seconds)
The injector is installed according to the technical conditions of the boiler and will be supervised by ECM technical service. ECM will perform a test dosage and train the staff. SP-ECO pays off (sample calculation coal fuel) Technical inputs Steam production: 208 t/h Efficiency factor: 86,97% Operating hours per year: 5 800 h Operating months: 8 Coal consumption: 33,4 t/h Coal/day: 801,6 t Savings 1 Raise of efficiency factor: 1 to 3 % (better results are possible but depend from boiler to boiler and current level of efficiency) Expected coal savings: 3 to 8 % Coal saving: 1,00 /tons/hour = 24,05 t/day = 3,0% Coal savings year: 5.796,05 tons Cost /ton of coal: 60 EUR Cost / 100 g/ SPS: 1,10 EUR Cost 5.796,05 t coal/year: 347.763,00 EUR Cost SPS/year: 19.319 kg =210.529,00 EUR SAVINGS: 137.234,00 EUR Savings 2 1 t of coal produces = 2,86 t of CO2 5.796,05 t/year x 2,86 t = 16.576,70 t CO2 x 4,80 /t = 79.568,16 Savings 1 + Savings 2 =216.802,16 EUR Other savings (not calculated) Costs of transporting slag to landfill the reduction of corrosion damage prevent damage made by heavy debris falling
FTIR Analyzers Over 500 systems installed worldwide More than 160 AIT refinery systems, FTIR and NIR, lab and on-line Global sales and support network Sample Conditioning systems Services / Installation / Chemometric support Mature systems optimized over 4 generations of development Flexible, configurable run-time package Works with all commercially available chemometrics packages, providing flexibility Analect Hydrocarbon SmartSystem (HSS) Extended-MidIR Process FTIR Analyzer System ASTM D6122 Compliant SmartSampling Model Maintenance SpectraRTS Process Analyzer Operating Software SpectraQuant Chemometrics Software Analect Transept IV FTIR Interferometer Stable, Reliable, Modular Core of all Analect products Uniquely designed for operation in harsh environments Refractively scanned no moving reflective surfaces Higher tolerance to vibration, temperature variations Stable laser and highly reproducible optical system Seamless calibration transfer from lab to process analyzers No re-calibration after maintenance Ease of Maintenance Modular Source (12 month Preventative Maintenance) Modular Laser (42 month Preventative Maintenance) RemoteRX Diagnostics Module Monitors critical interferometer health signals Simplifies diagnostics Enables predictive maintenance
Analect Hydrocarbon SmartSystem (HSS) NEMA4X painted stainless steel enclosures Purged, pressurized for hazardous areas Power line conditioning: voltage regulation and surge suppression Temperature control: vortex cooled with overtemp warning and shutdown Vibration isolation: enhanced stability Optional Configurations Dual Cell Hydrocarbon SmartSystem The main features of the SmartSample System are: Stream Selection Sample Conditioning / Monitoring Automatic Zero And Validation Automatic Sample Capture Manual Validation Sample Introduction
Temperature Control / Monitoring Heat exchangers for sample temperature control to +/- 1 o C Sample temperature trended, alarms set if out of range Water Removal: Flow control / Monitoring: Membrane separator for removal of suspended immiscible water from sample Flow indicator with low flow switch on sample cell Flow indicator with low flow switch on sample capture loop Optical Analyzer Calibration
Model Data Input CPSA Modeling Software Unique modeling platform to suppress/eliminate spectral interferences H20, CO2, other contaminants Pathlength/Density variations (e.g. with temperature, cell maintenance) Baseline offset, tilt, curvature (including non-ideal interferometer effects) Three calibrations were built using the same data set and same regions: CPSA With full constraints PCR With two point baseline preprocessing PCR With first derivative preprocessing One calibration spectrum was intentionally distorted Added offset +0.05Au Added slope +-.08Au Added curvature +0.1Au - 0.05Au Added 10X normal noise Added water vapor 0.05Au Increased pathlength 5% Key algorithm developed by ExxonMobil Spectraquant is a significant improvement over PCA PCA is a method for finding the largest sources of variation in (spectral) data - each is known as a factor, thus PCA is also known as factor analysis each factor describes the largest variation that has not yet been accounted for PCA can be considered a spectrum pre-treatment the spectra are analyzed to find the largest source of variation among them