Radiation thermometry standards at NMIJ from −30 °C to 2800 °C

NMIJ has established a national standard scale in radiation thermometry from −30 °C to 2800 °C. At low temperatures from 160 °C down to −30 °C large aperture fluid-bath blackbodies have been constructed for the calibration of thermal infrared thermometers. In the range from 160 °C to 420 °C, the standard scale has been realized on 1.6 μm thermometers calibrated against In, Sn, and Zn blackbodies. A variable temperature blackbody using an air-bath furnace has recently been developed for direct comparison measurements of a 10 μm thermometer with a 1.6 μm thermometers up to 500 °C. In the higher range of the temperature scale, dissemination consists of three schemes: the range from 400 °C to 1100 °C by Zn, Al, Ag and Cu fixed-point blackbodies: above the Ag point by 0.9 μm and 0.65 μm thermometers: and above the Cu point by metal-carbon high-temperature fixed points.