GB/T 20151-2006

This standard specifies the characteristics of the physical photometry system established by the CIE, which are recognized as the basis for light measurement. This standard defines photometric quantities, units, and standards that constitute the CIE system of physical photometry and are officially recognized by the International Committee for Weights and Measures (CIPM). These include: - Definitions of photometric quantities and units; - Definitions of the CIE standard spectral luminous efficiency functions for daylight and night vision; - Definitions of CIE standard photometric observers that conform to these functions; - Definitions of maximum luminous efficiency for daylight and night vision. An informative Appendix A provides a glossary of related terms.