Interlaboratory Comparison 2023 (IC 2023)

Interlaboratory Comparison 2023 (IC 2023) for Temporal Light Modulation (TLM) measurement

The SSL Annex launched its 2023 Interlaboratory Comparison (IC 2023) of temporal light modulation (TLM) measurements in September 2023.  Please click on these links to view the Official Announcement Letter:  (IC Announcement Letter in EnglishAnnouncement Letter in Japanese; Announcement Letter in Korean).  IC 2023 is open to all photometric labs that have capability for measuring TLM quantities, in particular, short-term flicker indicator (PstLM), and stroboscopic effect visibility measure (SVM), of LED lighting products. Laboratories that conduct or plan to conduct testing of LED lamps and luminaires for these TLM quantities are encouraged to participate in IC 2023. This comparison is being organised primarily to investigate the degree of agreement in the measurements of these TLM quantities among the participants as technical study as well as to provide verification of each participating laboratory’s measurement capabilities.

IC 2023 is thus designed in compliance with ISO/IEC 17043 to serve as a proficiency test for SSL testing accreditation programmes that recognise this comparison, as was done in the SSL Annex’s IC 2013 and IC 2017. IC 2023 will use IEC TR 61547-1 and IEC TR 63158 as the test methods for determining quantities PstLM and SVM respectively. 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.

Participating laboratories will be given a set of four non-directional LED lamps for testing PstLM, SVM, and optionally, flicker index, Mp, and other quantities. Participants can also choose to participate in an optional Technical Study where they will be sent (separately) a light waveform generator with five programmed specific waveforms for measurement, which may be useful to analyse possible problems in participants’ measurements.

To make this comparison even more useful, IC 2023 will be linked to two other regional TLM interlaboratory comparisons being organised in Europe (MetTLM) and in China (China GBV-LC TLM).  Both of these regional IC’s will include, in their testing, the same four lamp artefacts and quantities measured as IC 2023, effectively expanding the number of participants compared.

Registration was open from 25 September to 31 December 2023.  The price for participating in IC 2023 was set out below with a registration discount for any laboratories that are located in SSL Annex member countries (Australia, Denmark, France, Korea, Sweden and the UK).  This price includes participation in IC 2023 as well as all the courier costs associated with shipping the artefacts to and from your laboratory. If you have additional TLM measurement instruments that you would like to test in the IC, the cost of those is shown in the right column. Each instrument will be issued with an individual test results report.

There will be two or three rounds of measurements, depending on the level of interest which will be conducted sequentially in the period from October 2023 to February 2024.  Participants will be assigned from the first round in the order of payment received (or they can request a later round).

The SSL Annex publishes the Technical Protocol for IC 2023 which describes the details of the comparison artefacts (four LED lamps and a TLM generator), as well as the TLM quantities to the measured and the measurement conditions.  Those who do not measure all quantities listed in the protocol can still be accepted as participants in IC 2023.  Participant registration forms are available in English, Japanese and Korean.