© 2012 LUX-TSI Limited What is LM79 & LM80? Why are they important? Dr Gareth Jones CEO LUX-TSI & TheDoctor for LUX Magazine

© 2012 LUX-TSI Limited www.lux-tsi.com

What is LM79 & LM80? Why are they important?

Dr Gareth JonesCEO LUX-TSI & TheDoctor for LUX Magazine


Why do we need Standards for LEDs?

• Market is flooded with LEDs claiming to replace conventional lamps and luminaires

• Some achieve this, but many fall far short – LED lamps claiming to replace a 100W

lamp may typically deliver less light than a 40W lamp!

• Limited market surveillance to identify these cases, and a lack of standards means they cannot easily act

• This is damaging consumer perception of LEDs in general – Negative impact on rate of LED acceptance– Avoid same bad feeling as early CFLs!


• I believe that the Americans have, in LM80 and LM79, developed effective and practical standards for testing of LED chip, lamp and luminaires.

• These have been widely adopted in the US as de facto standards.

• I believe European manufacturers should, in the absence of European standards with wide acceptance, adopt LM79 and LM80 until formal standards come into force in europe.

TheDoctor’s Mantra


Disclaimer - European Standards

• IEC/CEN is working on a revision to EN13032-1 but it is not clear when the new revision EN13032-x will come into force.

• IESNA LM-79 and LM-80 have been in force since 2008 and are rapidly being adopted around the world for LED.

• It is not that EN13032 is not good – it is that EN13032 does not cover LEDs yet and in the absence of this we advocate we should use LM-79-08


• Accreditation is Important– Ensures a consistent minimum level of

competence - independently audited and verified– Traceability of calibration so we avoid the

“Chinese Lumen” problem• Round Robin Testing between Labs is

Encouraged and is Important to ensure labs achieve consistency for Global Markets

• Standards are Important– Ensure that all labs and manufacturers are given

guidance on best practise.


Would you use a Cowboy builder? I doubt it.

You would look for some form

of accreditation


What to look for in Lighting Photometric Test Labs

• Key global requirement for photometry & colorimetry is that testing laboratories have proven competence through ISO17025 audited by an ILAC affiliated organisations.

• In the UK, this is UKAS.


Worldwide Lighting Test Laboratory Accreditation

• IECEE CB Scheme for IEC Safety Approvals (iecee.org)

• ILAC-MRA Bodies for Competence in Testing with ISO17025 (UK – ukas.com)

• UL DAP Programme for submission of test reports against UL Standards ( ul.com)

There are others but these are the main ones.


Types of Testing

Performance

Safety

Form(Zhaga)

Labelling

Electrical

Thermography

EMC Emission & Immunity

Photometry

Photobiological

Lumen Maintenance

Endurance

Environmental

Mechanical


Types of Testing

Performance

Safety

Form(Zhaga)

Labelling

Electrical

Thermography

EMC Emission & Immunity

Photometry

Photobiological

Lumen Maintenance

Endurance

Environmental

Mechanical


LM-79 “Electrical and Photometric Measurements of Solid-State Lighting Products”• IESNA Approved method describing procedures and

precautions in performing reproducible measurements of SSL Products for Illumination Purposes:– Total Luminous Flux (lumens)– Luminaire Efficacy (lm/W) – Colour (Chromaticity, CCT, CRI)– Intensity Distribution

Referenced to CIE, ANSI & IESNA


Lamps & Luminaires


Key Stipulations• Ultra stable Temperature +/- 1C• Voltage regulation < +/-0.2%• Thermal Stabilisation < 0.5% over

30 minutes• Test in Orientation of Use• Type C Goniometry only• Test Report minimum standard• Spectroradimetry preferred

(photometer much less preferred but accepted if the spectral mismatch correction is provided – see TheDoctor – The Wheat & the Chaff)


Essential Items• Stable Power Source – Ensuring all

changes in performance are due to the product.

• Calibrated Power Meter – To measure the true power and calculate the power factor and harmonics

• Calibrated Temperature Monitor25C +/- 1C !

• Calibrated Air Flow Meter – No draughts!


Integrated Flux

Integrating Sphere

Spectroradiometer(or corrected Photometer)

Calibration Lamps


Measure Spectral Flux with Wavelength

• Compute– Total Integrated Flux (Lumens -Lm)– Colour Rendering Index (CRI) R1-R14– Correlated Colour Temperature (CCT)– White Light Appearance – Tint (Duv)– Chromaticity (x,y u’,v’)– Luminous Efficacy (Lm / W)


Goniometric IntensityType B Near-Field Imaging(not LM79 compliant)

Type C Far-Field Intensity(LM79 Compliant)


Measure Intensity Distribution with Angle

LED Without Optics LED With Optics


Measure Intensity with Angle

• IES Files• LDT Files• Polar Plots• Cone

Diagrams• Isolux• IsoCandela

Output key Plots and File Depending on Preference

• Glare, UGR• Roadway

Utilisation• Zone

Summaries


Thermal StabilizationESSENTIAL FOR ALL LED MEASUREMENTS – KEY ISSUE• Ensure normal convection of air flow as to not affect the LED Temperature.• The effect of Temperature on LED performance is a key issue• Can give rise to errors as much as 30% in Luminous Flux• Can lead to big difference in CCT for colour mixed LEDs

08/06/2011

350 400 450 500 550 600 650 700 750 800 8500.00E+00

5.00E-04

1.00E-03

1.50E-03

2.00E-03

2.50E-03

3.00E-03

0 minutes15 minutes30 minutes45 minutes60 minutes

Wavelength (nm)

Flux

(W/n

m)


LM-80 “Approved method for measuring lumen depreciation of

LED light sources”• “Light Sources” includes LED packages, arrays and modules.

• Does not cover measurement of lamps and luminaires.

Referenced to CIE, ANSI, LM79 standards


LM-80 “Approved method for measuring lumen depreciation of

LED light sources”

• Provides guidance for measuring lumen maintenance

• Requires testing for at least 6000 hours at 3 different junction temperatures

• Does not define or provide methods for estimation of life.

• Requires TM-21 as the analysis method for determining the lumen maintenance value from the measurements.

Referenced to CIE, ANSI & IESNA


LM-80 - Useful• Ensures lifetime of the LED is tested at component

level – avoid the cost of testing of the final product assembly – this is a key design consideration!

• Specifies 3 realistic temperatures for the testing – 2 are fixed and one can be determined by the manufacturer

• Refers to LM79 for the basis of the testing of the photometric output of the sources - ensuring good practise (Did you spot the discrepancy?)

• Is being used to prevent expensive 6000+ hour testing at the luminaire/lamp level

• Is already referenced in UK schemes like ECA guidance


New Standard – LM82-12- Characterization of LED Light Engines and LED

Lamps for Electrical and Photometric Properties as a Function of Temperature.

Excludes luminaires.


Some emerging Standards

- IES LM-XX-12 Measuring Lumen Maintenance of LED Lamps, Light Engines and Luminaires

- IES LM-XX-?? LED Package Reliability Testing – Qual/Overstress/Failure Specification & standardise on LED test specification for manufacturers

- CIE TC2-71 Standard on Test Methods for LED Lamps, Luminaires and Modules

- CIE TC 2-74 Gonio-spectroradiometry of Optical Radiation Sources

- & others EN13032-??


Quick Summary• Accreditation of test labs is important to ensure

known minimum standards of competence, traceability and comparability around the world.

• LM-79 and LM-80 good reference for test labs and manufacturers. Also, appearing in some Government incentive schemes.

• Looking forward to EN13032 and other EN stds.

• New standards from IESNA and CIE emerging fast to provide guidance on good practise for LED lighting. Adopt in the absence of better guidance.


Meet us at NEC Birmingham for

UL/LUX-TSI Roadshow on LED Lighting Standards and

Regulation1-day free event

12th June (bit.ly/N2O74V)

euroLED.org.uk13th & 14th JuneStand LED 218


UL/LUX-TSI Roadshow on LED Lighting Standards and Regulation1-day free event 12th June (bit.ly/N2O74V)

• 10:00 - 10:15 Welcome and Introduction – SSL Global Trend Roberto Inclinati – Business Development Manager, UL

• 10:15- 10:45 UL & IEC Standard update Albert van der Veen – Project Engineer, UL

• 10:45 - 11:15 UL8750 for Decorative and Architectural LED Lighting Products to Access to the U.S Market with references to IEC requirements Albert van der Veen – Project Engineer, UL

• 11:15 - 11.30 Coffee Break

• 11:30 - 12:30 Energy Star & Lighting Facts- Legislation and Requirement for North America Gareth Jones – LUX-TSI Ltd.

• 12:30 - 13.30 Buffet Lunch

• 13:30 - 14:30 ErP - Legislation and Requirements for Europe Gareth Jones – LUX-TSI Ltd.

• 14.30 - 15.30 Zhaga - Book 2 & Book 3 Luca Tibaldini – Engineering Manager

Documents

© 2012 LUX-TSI Limited What is LM79 & LM80? Why are they important? Dr Gareth Jones CEO LUX-TSI & TheDoctor for LUX Magazine