Evaluation of temporal light artefacts in tunable white solid state light sources

The Temporal Light Artefacts (TLAs) represent a significant concern in the field of lighting technology, impacting visual comfort and potentially causing health issues. Among the various metrics, the short-term flicker index (PstLM) has emerged as a robust indicator, reflecting the human eye's sensitivity to temporal variations in light intensity. Apart from the P stLM, the stroboscopic visibility measure (SVM) is another metric that was developed to assess the likelihood of stroboscopic effects, such as flicker or motion perception, in artificial lighting systems. This paper explores the evaluation of tunable white LED luminaires in terms of temporal light modulation. The evaluation concerns the measurement of both PstLM and SVM following the requirements of the recently introduced standards IEC TR 61547-1 and IEC TR 63158 as well as the EU Eco-design Regulation. The results are then compared with other LED lighting products as well as legacy light sources, i.e. incandescent and fluorescent lamps. Useful conclusions can be deduced from the measurements that can be used for the assessment of temporal light modulation in solid state light sources both conventional and tunable white.