Interlaboratory Comparison of Temporal Light Modulation Measurements (IC 2022)

Pre-Announcement and Request for Expression of Interest in the
IEA 4E SSL Annex’s 2022 Interlaboratory Comparison of
Temporal Light Modulation Measurements (IC 2022)

CLICK HERE to download an IC 2022 Expression of Interest Form (non-binding).  Return by 30 June 2022.

Many national and regional regulations and voluntary programmes on energy efficient lighting products now require limits for temporal light modulation (TLM) quantities for LED lighting products. This highlights the importance and urgency of verifying the level of agreement in measurements of TLM quantities.

Building on the success of our 2013[1] and 2017[2] interlaboratory comparisons where collectively 146 labs from around the world were compared for measurements of LED lighting products, the IEA 4E Solid State Lighting Annex (SSL Annex) is assessing market interest in conducting a 2022 Interlaboratory Comparison (IC 2022) for temporal light modulation (TLM) measurements.

IC 2022 would be open to all photometric labs that have capability for testing TLM quantities, in particular, Short-term flicker index, PstLM, and Stroboscopic effect visibility measure, SVM, of LED lighting products. If there is sufficient market interest, the SSL Annex will progress with IC 2022 and publish the Test Protocol describing detailed test methodology. Participants will then have several months to formally register for the comparison. Participant measurement rounds would start in late 2022 and continue in 2023.

Lighting laboratories that use or plan to use their photometric systems for measuring TLM quantities of LED lamps and luminaires are encouraged to participate in IC 2022. This comparison is being organised primarily to compare TLM measurements of LED light sources as well as investigate measurement variations between photometric systems and the capability of participating laboratories using their photometric systems to measure SSL products.

IC 2022 will be designed in compliance with ISO/IEC 17043[3] to serve as a proficiency test for SSL testing accreditation programmes that recognise this comparison, as was done in IC 2013 and 2017. IC 2022 will use IEC TR 61547-1[4] and IEC TR 63158[5] as the test methods for determining quantities PstLM and SVM respectively, and if recognised by accreditation bodies, the participant results reports may be used as a proficiency test not only for IEC TR 61547-1 and IEC TR 63158 but also regional versions of these test methods. The results can also be used for benchmarking.

The comparison will be conducted in a similar way to the SSL Annex’s previous comparisons, where participants are assigned to a Nucleus Laboratory, each of which will conduct measurement rounds with laboratories in different regions of the world.

Participating laboratories will be asked to measure a set of SSL product artefacts for short-term flicker of illumination, PstLM, and stroboscopic effect visibility measure, SVM, as well as to report waveforms and five electrical quantities. Participants will be asked to use the IC 2022 test protocol which will be consistent with test methods described in IEC TR 61547-1, IEC TR 63158 and CIE TN 012:2021 but those who are not in full compliance with these test methods and/or those who do not measure all the quantities above will still be accepted as participants in IC 2022.

After completion of all participants’ measurements, each participant will receive an individual test report that could serve as a proficiency test (PT) report, as well as a preliminary IC 2022 final report at the end of the comparison that will analyse all the results anonymously for a technical study as was done in IC 2013 and IC 2017. Laboratories that are not interested in PT for accreditation may still find participation in IC 2022 of interest for benchmarking purposes.

The price for participating in IC 2022 will be in a range of €2400 to €3800 per lab, depending on the number of labs expressing interest.  The SSL Annex will offer a discount for labs located in SSL Annex member countries (Australia, Denmark, France, Korea, Sweden and the United Kingdom) and for multiple instruments at the same lab.

If you are interested in participating in IC 2022, we would greatly appreciate receiving an indication of your interest. Please complete the attached table below for Expression of Interest and send it to by the 30th of June 2022 with any questions you may have. This expression of interest is non-binding, but it will help us determine whether there is sufficient market interest/need for an interlaboratory comparison on TLM measurement and, if the decision is taken to progress with IC 2022, prepare sufficient artefact sets and resources needed to ensure the IC runs on schedule.

All laboratories that submit an Expression of Interest will be informed directly once the final decision is made on IC 2022 and at that time, they will be invited to formally register.

CLICK HERE to download an IC 2022 Expression of Interest Form (non-binding).  Return by 30 June 2022.


[1] IEA 4E Solid State Lighting Annex: 2013 Interlaboratory Comparison Final Report
[2] IEA 4E Solid State Lighting Annex: 2017 Interlaboratory Comparison Final Report
[3] ISO/IEC 17043:2010 Conformity assessment — General requirements for proficiency testing
[4] IEC TR 61547-1:2020 Equipment for general lighting purposes – EMC immunity requirements – Part 1: Objective light flickermeter and voltage fluctuation immunity test method
[5] IEC TR 63158:2018 Equipment for general lighting purposes – Objective test method for stroboscopic effects of lighting equipment