IEC 61322:2020 applies to installed dose equivalent rate meters, warning assemblies and monitors, as defined below. It covers equipment intended to measure neutron radiation in dose equivalent rates in the energy region between thermal and 20 MeV for the purposes of radiation protection.
Assemblies of this type are commonly defined as area radiation monitors. They are normally employed to determine continuously the radiological situation in working areas in which the radiation field may change with time, for example, nuclear power plants, particle accelerators, high-activity laboratories, fuel reprocessing plants, etc., and provide alarms when the radiation field goes outside predetermined limits.
The assemblies considered in this document comprise at least:
- a detector assembly, which may, for example, consist of a detector probe (for thermal neutrons such as BF3 proportional counter, 3He proportional counter, 6LiI(Tl) scintillation detector, etc.) and a moderating and absorbing medium surrounding the detector;
- a processing assembly, which may be fitted into a centralized panel, which, in the case of warning assemblies and monitors, provides signal outputs and contacts capable of activating alarm or other trip circuits;
- alternatively, the case when all the processing electronics are placed within the detection unit (so called smart blocks) may be considered. In this case the functions of the processing assembly will be composed of only the indication, the providing signal outputs and contacts.
This second edition cancels and replaces the first edition published in 1994This edition includes the following significant technical changes with respect to the previous edition:
- this document has been updated to take account of the requirements of the relevant IEC standards, IEC 60532:2010 and IEC 61005:2014.