The IES approved method for electrical and photometric testing of solid-state lighting products as complete units. Because LED performance depends on the whole luminaire's thermal and electrical design, it uses absolute photometry, measuring the actual product rather than scaling from a lamp. The report gives lumens, input watts, efficacy, CCT, CRI, chromaticity and, from a goniophotometer, the intensity distribution.
Rebate program needs an LM-79 report from an accredited lab, the manufacturer's own data sheet won't cut it.
Also heard as
- LM-79 report
- LM-79 test
Do not mix it up with
- LM-80: LM-80 tests how LED packages hold their output over thousands of hours; LM-79 measures a finished luminaire's performance at one point in time.
Related terms
LM-80
The test method for tracking how LED packages lose light over time, the basis of lifetime claims.
Goniophotometer
An instrument that measures a luminaire's light intensity in every direction by turning the luminaire, or a mirror around it, relative to a detector.
Integrating sphere
A white-lined hollow ball that spreads a source's light evenly so one detector can read its total lumens and color.
Luminous efficacy
How many lumens a light source or luminaire produces for each watt of electric power, in lm/W.
Cut sheet
The one- or two-page manufacturer data sheet for a luminaire, with dimensions, photometry and ordering options.