The U.S. Government issued her LED test standards IESNA-LM-79-08 which is a guide developed for the measurement of Solid State Lighting products such as LED Street Light, LED Flood Light, LED Down Light, LED Ceiling Light, LED Par Light, LED Tube, LED Module and so on.
The most of LED fixtures manufactory use the Integrating Sphere to test the color and photo parameters. But considering to the SSL’s feature is not like a light source, it requests a Goniophotometer to do the test. According to CIE121-1996, there are two kinds of goniophotometers.LSG-1800B is a goniophotometer which rotates the luminaire around two mutually Perpendicular axes whose intersection is the photometric centre of the goniophotometer. LSG-2000 is a goniophotometer in which the luminaire does not move at all.
The solution of goniophotoneter is LM-79.which establishes testing methodology to create a level field for product evaluation. It looks at