Home / Standards / GB/T 20151 GB/T 20151 Active Photometry—The CIE system of physical photometry 光度学 CIE物理光度系统 Standard Type GBT ICS 17.180.20 CCS K71 Status 现行 Issue Date 2026-01-28 Implementation 2026-01-28 Responsible Dept 中国轻工业联合会 Drafting Unit 中国轻工业联合会