Two Colour Pyrometer

Abstract

In the customary total radiation pyrometer or optical pyrometer, the indication of the temperature depends on the emissivity of the radiator. In the two colour pyrometers, the temperature is obtaind by measuring the ratio of intensities of radiation at two different wavelengths, then its indication is free from emissivity, as far as it is equal over the all wavelengths, that is gray body condition.
The authors tried to compare the intensities at two colours by new method. In this device, the energies at two colours are put into the photomultiplier alternately, and one of the outputs is reduced automatically by rotating the polalizer disc till it becomes equal to the other. From the rotated angle of the disc, the temperature of the radiator can be known.