International comparisons of the CCPR-S1 units of spectral radiance at wavelengths of 220–2500 nm

Abstract

The Consultative Committee for Photometry and Radiometry (CCPR) has organized international comparisons of the CCPR-S1 units of spectral radiance at wavelengths of 220–2500 nm with participation by the BNM-INM (France), NIST (USA), NRC (Canada), PTB (Germany), and VNIIOFI (Russia), with the latter as the pilot laboratory. The methods and equipment for these measurements, as well as the results of the comparisons, are discussed. The comparisons showed that the discrepancies between the spectral radiance scales were basically within ±1.5%. This discrepancy decreases to ±1.0% if the data from highly unstable transfer standards are eliminated from the analysis.