Occupationally exposed workers need to have a basic awareness and understanding of the risks posed by exposure to radiation and the measures for managing these risks. To assist persons who have a responsibility to provide the necessary education and training of these workers, the series of Practical Radiation Technical Manuals (PRTMs) was created. Sources of ionizing radiation have a large number of applications in the workplace. The exposures of the individual workers involved may need to be routinely monitored and records kept of their cumulative radiation doses. There are also occasions when it is necessary to retrospectively determine a dose which may have been received by a worker. This manual explains the basic terminology associated with individual monitoring and describes the principal types of dosimeters and other related techniques and their application in the workplace.