Notice of Removal: Determination of blackbody cavity reflectance at 633nm by integrating sphere reflectometer

The blackbody cavity emissivity is a primary parameter of blackbody source. The measurement of blackbody cavity emissivity could verify the design value of cavity emissivity. A determination of graphite blackbody cavity emissivity by reflectance measurement is presented. The measuring equipment include a He-Ne laser, laser power stabilizer, integrating sphere, Si photoelectric detector, gray reflectance standard sample and Keithley 6485 picoammeter. The preliminary measurement value of graphite blackbody cavity emissivity is 0.99983351.