Overview of measurement standards for solid state lighting

Transcription

1 CORM 2009 NIST Tutorial Workshop, Gaithersburg, MD, May 5, 2009 Overview of measurement standards for solid state lighting Yoshi Ohno Director of CIE Division 2 Member of ANSI C78-09, IESNA TPC National Institute of Standards and Technology Gaithersburg, Maryland USA 1

2 Solid State Lighting is becoming a reality 2

3 Current State of White LEDs Luminous Efficacy Goal From presentation by Fred Welsh at 2009 DOE SSL Program Planning Workshop, Feb. 2009, San Francisco. 3

4 Problems/Concerns in the industry Some very low quality products in the market (dim, short life, bad color). Inaccurate performance claims Insufficient information on product labels Many questions on color quality (rendering) Lighting designers still do not trust SSL products. They say more standards are needed. Still high cost (but government incentives to use SSL products are high.) * US DOE is addressing these problems with the Energy Star, CALiPER and other programs. 4

5 DOE s Solid State Lighting Program Strategy CALiPER From presentation by James Brodrick, DOE Energy Star Workshop, May 15,

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7 SSL Quality Advocates Program jointly developed by DOE and NGLIA a voluntary pledge program to assure that LED lighting, as it reaches the market, is represented accurately. introduces the Lighting Facts label, similar to the FDA Nutrition Facts label. provides a quick and simple summary of product performance data as measured by the new industry standard for testing photometric performance, IESNA LM

8 DOE SSL Energy Star (Category A) 1. Under-cabinet kitchen lights 2. Under-cabinet shelf-mounted task lights 3. Portable desk/task lights 4. Recessed down lights 5. Out-door wallmounted portch 6. Out-door step lights 7. Out-door pathway 8

9 SSL Energy Star Specifications Program started from Sep. 30, Required standards for Test method and measurement.. IESNA LM-79 Chromaticity specification. ANSI C Test method for lifetime of LEDs.... IESNA LM-80 Laboratory accreditation for measurement.. NVLAP EELP-SSL Terminology... ANSI/IESNA RP-16 addendum a 9

10 Addendum to ANSI/IESNA RP Published in May 2008 Addendum a to ANSI/IESNA RP (under continuous maintenance) 6.8 Light Emitting Diode LED die LED Bin Power source Power supply LED control circuitry LED driver LED driver, Class II LED luminaire LED package LED array LED module LED lamp, non-integrated LED lamp, integrated 10

11 Addendum a to ANSI/IESNA RP

12 Revision of this Addendum is being discussed at IESNA TPC. 12

13 Published, May

14 IESNA LM-79 Approved Method for Electrical and Photometric Measurement of SSL Products Covers LED luminaires and integrated LED lamps. Covers measurements of Total luminous flux (lumen) Luminous efficacy (lm/w) Chromaticity, CCT, CRI (4 π integrated) Angular intensity distributions Methods using Sphere-spectroradiometer Sphere-photometer Goniophotometer 14

15 ANSI C Specifications for the Chromaticity of SSL products Published Feb For indoor applications only No standards for outdoor applications 15

16 Published, Oct

17 IES LM Approved Method for Measuring Lumen Maintenance of LED Light Sources Scope. This document provides the methods of the measurement of lumen maintenance of sources including LED packages, arrays and modules only. This approved method does not provide guidance or make any recommendation regarding predictive estimations or extrapolation. IES TM-21-xx Lumen Maintenance Life: L 70 (hours): 70% lumen maintenance L 50 (hours): 50% lumen maintenance Testing at the LED case temperatures 55 C, 85 C, and a 3rd temperature selected by manufacturer, for 0 to 6000 h or longer. Ambient temperature within - 5 C from the case temperature. Model 0 Model 1 Model 2 Model 3 Model 4 Model 5 Model 6 Model 7 Data 17

18 Many Standards needed for LED/SSL LED packages Complete SSL products (low power) (high power) Integrated LED lamps LED arrays / modules LED luminaires LED light engines 18

19 Current Status of Standardization Activities LED chips/ packages (low power) (high power) CIE 127:2007 CIE TC2-46 IES LM-80 Lumen maintenance IES TM-21 IESNA new project CIE TC2-63, 64 LED arrays / modules CIE TC2-50 LED clusters and arrays LED light engines (ASSIST Recommends..) IESNA new project SSL products (Integrated LED lamps & LED luminaires) IES LM-79 Photometric meas. ANSI C Chromaticity CIE TC1-69 Color rendering IEC xx (performance of selfballasted LED lamps) Safety UL 8750 CIE TC2-58 radiance/luminance Several projects in IEC TC34A Definitions (terminology) IES RP-16 addendum a IEC TS

20 Large Gap between LED manufacturers and Lighting Industry <LED manufacturer> LEDs measured in production. LEDs are measured with short pulses. LEDs are binned and rated at T j =25 C. LED performance varies with temperature Pulse vs. DC? <Lighting industry> LEDs in luminaires are hot (T j = 60 C to over 100 C) Photometric measurements in steady DC mode. Performance of LEDs = Performance of SSL products 20

21 IESNA LM-xx Approved Method for Electrical and Photometric Measurement of High Power LEDs Status: first draft High power LED: an LED device that requires a heat sink or other type of thermal management as an integral part of the operation. Covers LED packages and LED arrays Covers measurements in pulse mode as well as DC mode (NIST method) Covers measurements of Total luminous flux (lumen) Luminous efficacy (lm/w) Chromaticity, CCT, CRI Methods using Sphere-spectroradiometer Sphere-photometer Goniophotometer 21

22 Work in progress in CIE on LED/SSL Division 2 Physical Measurement of Light and Radiation (Director, Y. Ohno, USA) TC2-46 TC2-50 TC2-58 TC2-63 TC2-64 CIE/ISO standards on LED intensity measurements (J. Scarangello, USA) Measurement of the optical properties of LED clusters and arrays (J. Schuette, Germany) Measurement of LED radiance and luminance (K. Kohmoto, Japan) Optical measurement of High-Power LEDs (Y. Zong, USA) High speed testing methods for LEDs (G. Heidel, Germany) Division 1 Vision and Color (Director, R. Luo, UK) TC1-69 Colour Rendition by White Light Sources (W. Davis, USA) 22

23 Work in progress in IEC on LED/SSL IEC TC34 Lamp and Related Equipment SC34A Lamps and glow starters (MT PRESCO) SC34B Lamp caps and holders SC34C Lamp control gear SC34D Luminaires <Working documents> IEC Safety standard for LED modules IEC Safety standard for self-ballasted LED lamps IEC/PAS Performance standard for self-ballasted LED lamps IEC TS Terms and definitions for LEDs and LED modules in general lighting IEC Performance of control gear for LED modules IEC Photobiological safety; Guide 23

24 International Intercomparison of LED measurements Organized by APMP (Asia Pacific Metrology Program) Regional metrology organization, connected to International Committee of Weights and Measures (CIPM), Consultative Committee of Photometry and Radiometry (CCPR) 15 Participants (National labs) KRISS, Korea (Pilot lab) CENAM, Mexico CMS-ITRI, Taiwan LNE, France MIKES, Finland METAS, Switzerland MKEH, Hungary NIST, USA NMIJ, Japan NMi-VSL, Netherlands NMIA, Australia NPL, UK PTB, Germany SPRING, Singapore VNIIOFI, Russia Measurement quantities Total luminous flux CIE Averaged LED Intensity Chromaticity (x, y) Artifacts: 5-mm LEDs, 20 ma A set of 14 LEDs (red, green, blue, white) Schedule: Measurements: July 2007 Completion of report: Dec

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