IEC 63121-2020 pdf free download

IEC 63121-2020 pdf free download.Radiation protection instrumentation — Vehicle-mounted mobile systems for the detection of illicit trafficking of radioactive materials.
4.3 Uncertainties
The radiation field or ambient dose equivalent rate uncertainty should not exceed ±20 %,
except for the radiation background measurements, for which the uncertainty may be larger
than the value stated here. Unless otherwise stated, the uncertainties are specified with a
coverage factor k = 1.
4.4 Statistical fluctuations
For tests involving the use of radioactive sources to verify susceptibility to a climatic, electromagnetic, or mechanical condition (Clauses 7, 8, and 9), the radiation field produced by the sources to verify the vehicle-mounted mobile system response shall be adjusted to reduce the magnitude of the statistical fluctuations.
If the magnitude of the statistical fluctuations of the vehicle-mounted mobile system indication arising from the random nature of radiation alone is a significant fraction of the variation of the indication permitted in the test (i.e., fluctuations greater than 12 %), then the radiation field should be increased to reduce the fluctuation of the readings (to ensure that the mean value of such readings may be estimated with sufficient accuracy to demonstrate compliance with the test in question). If the radiation field cannot be increased to meet the required coefficient of variation (COV) then the number of readings should be increased as necessary. The CCV for the nominal mean reading shall be less than or equal to 12 %.
For measurements without sources (i.e., at the level of background radiation), the vehiclemounted mobile system is observed in order to verify that alarms and spurious indications are not produced by an influence quantity (e.g., temperature, humidity, RF, impact, vibration), as readings are expected to display large fluctuations. Therefore, testing without sources can be performed even when the CCV is larger than 12 %.
4.5 Background radiation during testing
Testing shall be performed in an area having a radiation background as defined in Table 1.IEC 63121-2020 pdf free download.