Study the performance and analyze the uncertainty of 1.6µm Irradiation Thermometer

An irradiation thermometer with 1.6μm center wavelength was established at National Institute of Metrology P.R. China, temperature range of which is from 420°C to 1085°C. This paper introduces the measurement principle, structure and calibration method of irradiation thermometer, the stability of the irradiation thermometer, the noise equivalent temperature difference (NETD) of the thermometer at Zn fixed point and the expanded uncertainty at Zn, Al and Cu fixed points. The stability is 0.05°C, 0.07°C and 0.05°C during four months at Zn, Al and Cu fixed points, respectively. The value of the NETD including 16 times measurement results is lower than 25 mk at freezing platform of Zn fixed point. The expanded uncertainty of the irradiation thermometer is 0.24°C, 0.26°C, and 0.22°C at Zn, Al and Cu fixed points, respectively.