Realization of the new national primary scale of spectral radiance and spectral irradiance

Abstract

Based on new high temperature blackbody (HTBB) BB3500M and optical feedback control system, the new national primary standard apparatus of spectral radiance and spectral irradiance are evaluated and established at National Institute of Metrology (NIM). The stability, uniformity, repeatability and measurement uncertainty of the apparatus are promoted greatly compared to the former facility. The measurement uncertainty of temperature was decreased to 0.64K (k=1) when BB3500M blackbody is operating at 2980K, which is traceable to the Pt-C and Re-C fixed point blackbodies of NIM. Wavelength measurement range of spectral radiance and spectral irradiance are extended to 220nm~2550nm and 230nm~2550nm respectively, which satisfy the full wavelength requirement of CCPR-S1 spectral radiance international comparison.