Design, construction and calibration of a photoelectric pyrometer

The pyrometer described herein is a portable temperature measuring instrument that has no thermal capacity and which does not rely on the eye and judgment of the operator for brightness or color matches. This instrument can indicate the temperature of' a body practically instantaneously over a wide range of' temperatures. For blackbody radiators the temperature indicated by the photoelectric pyrometer is within ± 1 % of its true temperature.