The Illuminating Engineering Society of North America (IES) is the recognized technical authority on illumination,founded in 1906, it is a world famous lighting test institute.
IES LM-79-08 is the testing standard for Electrical and Photometric Measurements of Solid-State Lighting Products which was released in 2008.
This approved method describes the procedures and precautions for performing reproducible measurements of total luminous flux, electrical power, luminous intensity distribution and chromaticity of solid-state lighting (SSL) products for illumination purposes under standard conditions.
• Covers LED-based SSL products with control electronics and heat sinks incorporated. It does not cover external operating circuits or external heat sinks (e.g., LED chips, LED packages, and LED modules)
• Uses absolute photometry rather than relative photometry (historically the lighting industry standard) for the measurement of SSL.