International standards on equipment for the measurement of dose equivalent from photon, beta and neutron radiations

During 1971 the IEC set up a working group with the task: ''To investigate the problems involved in the design of radiation protection instrumentation for measurements in terms of dose equivalent and to make appropriate recommendations taking into account the work of other international organisations such as ICRU and ICRP''. Following consideration of the then currently available ICRP recommendations and ICRU reports the earlier IEC drafts proposed two new quantities called the skin and depth dose equivalents. These quantities were defined as the dose equivalent at specified depths along a radius of a 30 cm diameter, tissue-equivalent sphere in a unidirectional radiation field incident parallel to the radius concerned. A depth of 0.07 mm was specified for the skin dose equivalent and 10 mm for the depth dose equivalent. With the publication of ICRU Report 39 on new operational dose equivalent quantities the IEC incorporated these new quantities into its standards. This report describes the IEC requirements for equipment for measuring the ambient and directional dose equivalent. Advice is given on methods of providing traceable calibration for these quantities and examples are included on the suitability of existing equipment for the measurement of the new quantities. (author)