A Wide‐Range Thermistor Radiometer for the Measurement of Skin Temperature and Environmental Radiant Temperature

The thermistor radiometer consists of a Wheatstone bridge formed of four thermistors, two of which are exposed to incident radiation and two of which are hidden from it and act as thermal compensators. The output from the bridge is suitably amplified and fed into a microammeter on which deflections are read in microamperes and related to radiant temperatures by means of calibration charts. Calibrations are made against standard blackbody radiators and at present have been carried out for use of the instrument in ambient temperatures between −50°C and +30°C for measuring radiant temperatures between −185°C and +60°C. The instrument has been used successfully in (1) the measurement of skin temperatures indoors at normal room temperature and outdoors in ambient temperatures as low as −45°C; and (2) the measurement of the radiant temperature of the sky and ground in temperate and in arctic climates.