A gamma-ray device for non-contact measurement of temperatures of solids

A gamma ray thermometer is described which consists of a gamma ray source of energy suitable for irradiating a solid, a Mossbauer absorber inserted into the path of gamma rays reflected by the solid, and a counter for determining the number of gamma rays which passed through the absorber. The noncontact measurement of the temperature of the solid is achieved by utilizing the temperature dependence of the probability of recoiless emission of scattered gamma rays resulting from temperature variation of the solid.