This 1986 book is an introduction to the then commonly used types of detectors of nuclear radiation. It was directed primarily at students taking a first course in which an understanding of such devices was required. The author opens with an introduction to the properties and characteristics of ionising radiations. The main body of text, however, comprises a description of the construction, operation and main applications of gas-filled, scintillation and semiconductor detectors. In addition, the principles of the main electronic processing modules and amplifiers are discussed. Finally, the book includes a description of instruments used for the measurement of doses and dose rates of ionising radiations, together with an introduction to dose units and permissible dose levels, which will make it of particular interest to health physicists and safety officers.