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
Optical Technology Division
National Institute of Standards and Technology
Gaithersburg, Maryland USA
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Solid State Lighting is becoming a reality
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Current State of White LEDs
Luminous Efficacy Goal
From presentation by Fred Welsh at 2009 DOE SSL Program Planning Workshop, Feb. 2009, San Francisco.
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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.
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DOE’s Solid State Lighting Program Strategy
CALiPER
From presentation by James Brodrick, DOE Energy Star Workshop, May 15, 2008
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http://www1.eere.energy.gov/buildings/ssl/benchmark.html
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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-79-2008.
http://www1.eere.energy.gov/buildings/ssl/advocates.html
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DOE SSL Energy Star (Category A)
1. Under-cabinet
kitchen lights
2. Under-cabinet
shelf-mounted
task lights
4. Recessed 5. Out-door walldown lights mounted portch
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6. Out-door
step lights
3. Portable desk/task
lights
7. Out-door
pathway
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SSL Energy Star Specifications
Program started from Sep. 30, 2008.
Required standards for
• Test method and measurement …….…….… IESNA LM-79
• Chromaticity specification ……………………. ANSI C78.377
• Test method for lifetime of LEDs …..…….…. IESNA LM-80
• Laboratory accreditation for measurement .. NVLAP EELP-SSL
• Terminology
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…………... ANSI/IESNA RP-16 addendum a
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Addendum to ANSI/IESNA RP-16-05
Published in May 2008
Addendum a to ANSI/IESNA RP-16-05
(under continuous maintenance)
6.8
Light Emitting Diode
6.8.1 LED die
6.8.2 LED Bin
6.8.3 Power source
6.8.3.1 Power supply
6.8.4 LED control circuitry
6.8.4.1 LED driver
6.8.4.2 LED driver, Class II
6.8.5 LED luminaire
6.8.5.1 LED package
6.8.5.2 LED array
6.8.5.3 LED module
6.8.5.4 LED lamp, non-integrated
6.8.5.5 LED lamp, integrated
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Addendum a to ANSI/IESNA RP-16-05
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Revision of this Addendum is being
discussed at IESNA TPC.
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Published, May 2008
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IESNA LM-79 Approved Method for Electrical and
Photometric Measurement of SSL Products
ƒ Covers LED luminaires and integrated LED lamps.
ƒ Covers measurements of
•
•
•
•
Total luminous flux (lumen)
Luminous efficacy (lm/W)
Chromaticity, CCT, CRI (4 π integrated)
Angular intensity distributions
ƒ
•
•
•
Methods using
Sphere-spectroradiometer
Sphere-photometer
Goniophotometer
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ANSI C78.377 Specifications for the Chromaticity of
SSL products
Published Feb. 2008
• For indoor applications only
• No standards for outdoor
applications
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Published, Oct. 2008
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IES LM-80-08 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:
L70 (hours): 70% lumen maintenance
L50 (hours): 50% lumen maintenance
Model 0
Model 1
Model 2
Model 3
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.
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Model 4
Model 5
Model 6
Model 7
Data
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Many Standards needed for LED/SSL
LED packages
(low power)
(high power)
Complete SSL products
Integrated LED lamps
LED arrays / modules
LED luminaires
LED light engines
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Current Status of Standardization Activities
LED chips/ packages
(low power)
(high power)
LM-80
CIE 127:2007 IES
Lumen maintenance
CIE TC2-46
IES TM-21
IESNA new project
CIE TC2-63, 64
LED arrays / modules
CIE TC2-50 LED
clusters and arrays
SSL products
(Integrated LED lamps &
LED luminaires)
IES LM-79 Photometric meas.
ANSI C78.377 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
LED light engines
(ASSIST Recommends ..)
IESNA new project
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Definitions (terminology)
IES RP-16 addendum a
IEC TS 62504
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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 Tj=25°C.
LED performance
varies with
temperature
<Lighting industry>
Pulse
vs.
DC ?
• LEDs in luminaires are hot
(Tj= 60 °C to over 100°C)
• Photometric measurements
in steady DC mode.
Performance of LEDs = Performance of SSL products
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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.
ƒ Covers LED packages and LED arrays
ƒ Covers measurements in pulse mode as well as DC mode (NIST method)
ƒ Covers measurements of
• Total luminous flux (lumen)
• Luminous efficacy (lm/W)
• Chromaticity, CCT, CRI
ƒ
Methods using
•
•
•
Sphere-spectroradiometer
Sphere-photometer
Goniophotometer
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Work in progress in CIE on LED/SSL
Division 2 Physical Measurement of Light and Radiation
(Director, Y. Ohno, USA)
TC2-46
CIE/ISO standards on LED intensity measurements (J.
Scarangello, USA)
TC2-50
Measurement of the optical properties of LED clusters and
arrays (J. Schuette, Germany)
TC2-58
Measurement of LED radiance and luminance (K. Kohmoto,
Japan)
TC2-63
Optical measurement of High-Power LEDs (Y. Zong, USA)
TC2-64
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)
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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 62031 – Safety standard for LED modules
IEC 62560 – Safety standard for self-ballasted LED lamps
IEC/PAS 62612 Performance standard for self-ballasted LED lamps
IEC TS 62504 – Terms and definitions for LEDs and LED modules
in general lighting
IEC 62384 – Performance of control gear for LED modules
IEC 62471-2 – Photobiological safety; Guide
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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)
Measurement quantities
CENAM, Mexico
CMS-ITRI, Taiwan
• Total luminous flux
LNE, France
• CIE Averaged LED Intensity
MIKES, Finland
• Chromaticity (x, y)
METAS, Switzerland
MKEH, Hungary
Artifacts: 5-mm LEDs, 20 mA
NIST, USA
NMIJ, Japan
A set of 14 LEDs (red, green, blue, white)
NMi-VSL, Netherlands
Schedule:
NMIA, Australia
Measurements: July 2007 –
NPL, UK
PTB, Germany
Completion of report: Dec. 2009
SPRING, Singapore
VNIIOFI, Russia
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Thank you for your attention.
Contact: [email protected]
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