LED Lifetime Lumen Degradation
All light sources degrade over time or most just “burn out”. LEDs, on the other hand, do not burn out but continue to degrade – eventually beyond useful light output, which is typically recognized as 70% of initial luminous flux (L70). Recognizing the need for an industry standard that would also help users evaluate LED products, in 2008 the Illuminating Engineering Society of North America (IES) published LM-80. Note, however that while LM-80 provides a standard method for testing lumen maintenance, it does not provide guidance or recommendations for predicting or extrapolating maintenance beyond the duration of these measurements. LM-80 is a standard that defines how the lumen output and colour shift of LEDs should be measured over time and at different temperatures. The full name of the latest version of this standard is “IES LM-80-20 Approved Method: Measuring Luminous Flux and Color Maintenance of LED Packages, Arrays and Modules”. LM80 Test LM-80 is important to lighting de...