AN ABSOLUTE THERMAL RADIATION CALORIMETER

Abstract

To allow the absolute calibration of field and laboratory radiometers in the range 0.1 to 1.5 cal/cm2 sec, a continuous flow radiation calorimeter has been constructed, based on a design originally developed by the British Joint Fire Research Organization. The temperature difference established between a water outlet and an inlet is sensed by a thermistor bridge and the radiation intensity measurement is made in terms of the level of the electrical power, applied to a built-in immersion heater, which is necessary to reproduce the same temperature difference.