IES LM-84-14

The method for measuring luminous flux and color maintenance of LED light sources has been documented in IES LM-80-08. At the solid-state lighting (SSL) system level such as LED lamps, light engines, and luminaires, other system components, in addition to the LED light sources, also contribute to luminous flux decay and color change over time. The system performance changes over time can be directly tested at the SSL product level. This document addresses the evaluation of the changes in performance of SSL systems over time and can be a useful tool for engineering evaluations and luminous flux maintenance for entire assemblies when environmental considerations and variability for the base LED deprecation is incorporated into the analysis.

Furthermore, performances of SSL systems, LED integrated lamps, non-integrated lamps, LED light engines, and LED luminaires, are typically but not without exception affected by operational and environmental variables such as operating cycle, conditions imposed by auxiliary equipment and fixtures, ambient temperature, airflow and orientation. This test method has been developed to establish consistent and environmental conditions across laboratories to achieve reproducible results and to permit reliable comparison of results.