Why does CALiPER test the entire luminaire rather than the LED device itself?
Lighting testing laboratories are instructed to follow test procedures specified in the draft version of LM-79 (IES Guide for Electrical and Photometric Measurement of Solid-State Lighting Products), which tests the luminaire as a whole — as opposed to traditional testing methods that separate lamp ratings and fixture efficiency. There are two main reasons for this: 1) there is no industry standard test procedure for rating the luminous flux of LED devices or arrays; and 2) because LED performance is temperature sensitive, luminaire design has a material impact on the performance of LEDs used in the luminaire. For these reasons, luminaire efficacy (total lumens emitted by the luminaire divided by the total watts drawn by the luminaire’s power supply) is the measure of interest for assessing energy efficiency of SSL products, as specified in LM-79.
