Flicker explained: interpretation of the Technical Report IEC 61547

Flicker, or more precisely temporal light modulation (TLM), has re-emerged as a problem with the introduction of LED-based lighting technology. TLM, meaning variations in light intensity over time, may have negative effect on human health, causing annoyance, headaches, eyestrain and migraine. the negative consequences of TLM create an obstacle to broad and rapid adaptation of the new LED-technology and consequently also an obstacle to potential energy savings.

This document gives a thorough introduction to TLM, what it is, and how it is measured. Mainly, it gives an explanation and interpretation of the technical report TR IEC 61547:1-20201 (henceforth referred to as IEC 61547, unless otherwise stated), published by the International Electrotechnical Commission (IEC), which describes the equipment, method and measures required to assess a specific type of TLM effect – flicker.

This document also includes a guide and description on how to build a TLM-setup from scratch based on the standards, and what should be considered when doing so.

The purpose of this document is to increase knowledge about flicker in particular and TLM in general, taking the technical report IEC 61547 as a starting point. This work aims to bridge the gap between technical standards and reports on the one hand and the lighting industry on the other. This is with the aim of ensuring that the new EU eco-design regulations are followed which in turn will mitigate health issues caused by TLM and support a sustainable transition to LED technology.