Interlaboratory Comparison for Temporal Light Modulation Measurement

The International Energy Agency (IEA) 4E SSL Annex has conducted an Interlaboratory Comparison (IC 2023) for the measurement of temporal light modulation (TLM) of solid-state lighting (SSL) products. Designed to meet proficiency testing requirements, IC 2023 compared measured TLM quantities of short-term flicker indicator $\left( {P_{{\text{st}}}^{{\text{LM}}}} \right)$ and stroboscopic effect visibility measure (SVM, MVS), as well as three other TLM quantities, of four comparison LED lamp artefacts. A comparison between the four Nucleus Laboratories was first conducted to establish reference values. The IC 2023 main round had 18 labs participate worldwide. The results showed much larger variations than expected. Analysis of the results identified the need for more robust test methods, with improvement in required performance specifications for TLM instruments, test equipment, and guidance on determining measurement uncertainties.