Measurement of solid-state lighting products
Solid-state lighting (SSL) products include LED luminaries and integrated LED lamps (replacement lamps with screw base). Measurement of SSL products, compared to lighting products using traditional incandescent and discharge lamps, requires unique test methods due to different products constructions and operating conditions of LED sources used. Thus, many existing standards for measurement of luminaries and lamps using traditional light sources cannot be directly applied to SSL products. Department of Energy (DOE)’s Energy Star Program required standard test methods for measurement of SSL products and also a laboratory accreditation program to certify laboratories for conformance to the standard test methods for SSL products. NIST made major contributions in developing the first standard for measurement of SSL products and a laboratory accreditation program.
For example, we lead the Illuminating Engineering Society of North America (IESNA) committee in the technical development of its recently published the first standard for measurement of SSL products, IES LM-79-8 Approved Method for Electrical and Photometric Measurement of SSL Products. It provides standard test methods for photometric and colorimetric measurements of SSL products, including luminous efficacy (lm/W), chromaticity, color rendering, and luminous intensity distribution. It also specifies operating conditions for SSL products for measurement, including ambient temperature, electrical measurements, aging, and stabilization, as well as recommended methods for optical measurements using sphere photometers, sphere-spectroradiometers, and goniophotometers. Consequently, this standard has been recognized as the key standard for test methods of SSL products and is used by DOE Energy Star program and the lighting industry in the USA.
At the request of DOE, these operating conditions and measurement methods have also been incorporated into the laboratory accreditation program for energy efficient lighting products by the NIST’s National Voluntary Laboratory Accreditation Program (NVLAP). This accreditation program is required for the implementation of the Energy Star program.
For more information see: