IEC 62598 pdf download.Nuclear instrumentation – Constructional requirements and classification of radiometric gauges
1 Scope and object
This International Standard applies to the manufacture and installation of electrical measuring systems and instruments utilizing radioactive sources (radiometric gauges, hereinafter called gauges). It also applies to source housings intended for use in the aforementioned measuring systems. This standard applies to equipment, which is not related to power production or to the fuel cycle. It does not apply to portable gauges which, because of their construction and purposes for use, are intended to be operated as mobile equipment and it does not apply to gauges operated with X-ray tubes, but it can be analogously applicable to these gauges. The object of this standard is to specify constructional requirements for the design of instruments utilizing radioactive sources in regard of radiation protection. This standard does not take into account mechanical or electrical hazards.
3 Terms and definitions
For the purposes of this document, the terms and definitions as specified in ISO 921 , IEC 60050-394 and IEC 60476, as well as the following apply. 3.1 collimation device device for restricting the radiation in one or more directions 3.2 detector housing that portion of the measuring head that includes the detector NOTE This assembly may be incorporated with the source housing, especially in the case of a back-scatter measurement system. 3.3 measuring head subassembly comprising one or several radioactive sources and detectors along with compensation sensors, if necessary, and devices that can be used to measure and correct the effects of undesirable influences NOTE The measuring head may consist of separate source-housing and detector-housing subassemblies and it may include electronic devices for signal processing. 3.4 permanently installed radiometric gauge radiometric gauge that is permanently installed at the measuring location NOTE The measuring location may also be situated on mobile equipment (e.g., on a ship or a vehicle). The detector housing and the source housing may be installed both rigidly fixed and movable. The mobility of the system is limited and determined by the purpose for which it was designed. 3.5 radiometric gauge control and measuring assembly consisting of at least one radioactive source, at least one detector and the mechanical devices required for non-destructive measurement of a process quantity 3.6 sealed source radioactive source that is sealed in a solid and inert capsule or is permanently incorporated in solid and inert materials so that dispersion of radioactive substances under normal conditions of use is substantially prevented; at least one dimension shall be ≥ 0,2 cm 3.7 source holder device used to support and fix the radioactive source NOTE In the context of this standard the term source holder means the part of the device which supports or holds the source, e,g., the shutter or a part of the housing. 3.8 source housing that portion of the measuring head which includes the radioactive source, its holder and primary shielding device and shutter mechanism, if any NOTE If the source housing is not part of a measuring head the term stand alone source housing is used (see 3.9). 3.9 stand alone source housing device which includes the radioactive source, its holder, primary shielding, collimator and optional shutter mechanism 3.1 0 useful radiation; useful beam portion of radiation that is emitted by the radioactive source and used for measurement
4 Classification of radiometric gauge types
4.1 Category A: Radiometric gauges with restricted beam Category A comprises gauges equipped with a device for collimation of the radiation, thereby restricting the useful beam. The gauge shall be designed in such a way that the radiation, except for the useful beam, is attenuated in conformity with the requirements of this standard (see Figure 1 ).
IEC 62598 pdf download
