Verification of blackbodies emissivity

Blackbody models are used as referential temperature measuring gauges for radiation thermometers calibration. Their emissivity is usually determined by calculation. The presented paper describes an experimental device used to measure local effective emissivities, using an optical radiometer. The methods to measure and evaluate emissivity and temperature are described. The results are compared with the theoretical model of a cylindrical-conical cavity used to calibrate radiation thermometers