This is a comprehensive text/reference for the operation and testing of infrared (IR) detectors. It provides introductory material needed by technicians and professional engineers entering the field. Infrared technology is a very active field at this time as a result of both the military's interest in IR and the availability of funds for research. The author provides formulas and examples for most laboratory applications. Detector types, radiometric concepts, test equipment, measurements and error analysis are also studied.