Solid State Lighting Annex: 2013 Interlaboratory Comparison Final Report

Yoshi Ohno, Koichi Nara, Elena Revtova, Wei Zhang, Tatsuya Zama, Cameron Miller “Solid State Lighting Annex: 2013 Interlaboratory Comparison Final Report”, IEA 4E SSL Annex Report; online  at

The Interlaboratory Comparison (IC 2013)  for the measurement of solid state lighting (SSL) products was conducted by International Energy Agency (IEA) 4E SSL Annex between October 2012 and August 2013. Fiftyfour laboratories from 18 countries participated in the comparison for measurements of photometric, colorimetric, and electrical quantities of several different types of SSL products. In addition, measurement data from the proficiency testing of 35 laboratories in the National Voluntary Laboratory Accreditation Program (NVLAP) Energy Efficient Lighting Products for SSL and in the National Institute of Standards and Technology’s Measurement Assurance Program are linked to IC 2013. And, data from further 21 laboratories from the Asia Pacific Laboratory Accreditation Cooperation (APLAC) proficiency test T088, are also linked to IC 2013, making it a comparison of test results from 110 laboratories and 123 sets of data. Measurements of luminous flux, luminous efficacy, active power, RMS current, power factor, chromaticity x, y, correlated colour temperature, and colour rendering index were compared. IC 2013 was also designed so that the results can be recognised as proficiency testing for SSL testing laboratory accreditation programmes worldwide. The differences of participants results from the reference values as well as z' scores (defined in ISO 13528) and En numbers (defined in ISO 13528 and ISO/IEC 17043) are all presented, and problems and findings observed from the results are discussed.

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