expands our current understanding of thermal imaging and, most importantly, provides a sound quantitative basis for evaluating the suitability of various thermal imagers for particular applications. Utilizing a practical approach that keeps theory and mathematics to a minimum, the text reviews the important performance parameters for industrial, laboratory, and surveillance applications as well as how these parameters can be measured. The author, T. L. Williams, a distinguished expert on designing and testing thermal imaging systems and recipient of the Callendar Medal from the Institute of Measurement and Control, focuses on the standard form of imaging camera but also includes descriptions of the different specialized forms of thermal imagers useful to anyone working with these systems. Providing detailed descriptions of the equipment and techniques that can be used for testing complete thermal imagers as well as in the testing of the main subunits of a thermal imager, this comprehensive reference will prove invaluable not only to those who use, test, and design thermal imagers, but also to anyone designing equipment or making measurements in the thermal band of wavelengths.