IES LM-20 PDF

IES LM-20 – Approved Method: Photometry of Reflector Type Lamps

This document describes photometric testing procedures and reporting guidelines for reflector type lamps and LED based lamps that mimic this traditional style of lamp. The application of the described procedures and guidelines will improve reproducibility within a laboratory, and will improve measurement agreement and facilitate comparison of results between laboratories. As used in this laboratory method, a reflector type lamp is a lamp having a reflective element(s) intended to redirect flux from the emitting element (e.g., filament, arc, LED) to form the intended spatial distribution of the light. For example, a reflective element might take the form of a reflective coating applied to the lamp bulb, or a reflector positioned relative to the emitting element and permanently affixed in this position. In addition, integrated LED lamps using reflective and refractive elements to create the intended spatial distribution are within the scope of this document.