IEC 61322-2020 pdf free.Radiation protection instrumentation – Installed ambient dose equivalent rate meters, warning and monitoring assemblies for neutrons with energies from thermal to 20 MeV.
For any part of the equipment (including sampling assembly if any), subject to appropriateplanned maintenance, the following requirements should be reached:
-MTBF(mean time between failure): > 20 000 h(with preventive maintenance).
In some circumstances, equipment may be required to operate in locations subject to seismicdisturbances. Any requirements for the equipment to operate in such conditions shall beagreed between manufacturer and purchaser, together with any additional test requirements.
Where radioactive sources are incorporated in the equipment,these sources，and thelabelling of the instrument,shall conform to the appropriate international and nationalregulations with regard to radioactive materials.
The time for which any radioactive source will be effective for its function shall be specified bythe manufacturer, and shall not be less than 5 years, unless adjustment of the source positionis provided to take account of the half-life of the source.In that case,adjustment shall not berequired more than once a year.
4.2Indication facilities
Processing assemblies shall be capable of giving a local indication. The equipment shouldhave the facility to transmit indication to remote locations.The equipment performance shallbe independent of any operational mode and be unaffected by failure of the remote location’sequipment. Additionally, a facility to allow the connection of a local chart recorder may beprovided.
In the case of an analog logarithmic scale meter，the processing assembly display shouldhave a scale length at least 20 mm per decade with appropriate divisional marks. A digitaldisplay may be used as long as a clear indication of the scales is provided. In the case of aprocessing unit with linear scales,the indication ratio between adjacent scales shall notexceed a factor of 10.
Alarm assemblies shall be capable of giving local audible and visual alarms. The visual andaudible alarm requirements shall be as agreed between the manufacturer and purchaser. Theequipment should have the facility to transmit alarms to remote locations.
Measuring assemblies which contain trip circuits shall，if possible, be designed to be “failsafe”, that is, be so arranged that interruption or failure of the power supply or componentfailure causing loss of signal shall result in actuation of a trip circuit to produce an alarm.Failure of the power supply should not disable the alarm. Indication of power supply failureshall be provided.
Alarm circuits shall be operable either to hold an alarm condition until specifically reset by areset control, or to auto-reset when the alarm state disappears. The two modes of operationshall be available by simple modification on all equipment.
All alarm functions shall be provided with test facilities to allow checking of alarm operation.In the case of adjustable alarms,checking shall be possible over the range of adjustment,with indication of the actual alarm operation point.
The following facilities normally should be provided.IEC 61322 pdf download.