BS ISO 8769:2020 Measurement of radioactivity一Alpha-, beta- and photon emitting radionuclides一Reference measurement standard specifications for the calibration of surface contamination monitors

BS ISO 8769:2020 Measurement of radioactivity一Alpha-, beta- and photon emitting radionuclides一Reference measurement standard specifications for the calibration of surface contamination monitors. National metrology institutes shall , at their discretion , provide the means whereby Class 1 reference measurement standards of a specified range of radionuclides may be certified by them . For those countries which are signatories to the Mutual Recognition Arrangement ( MRA ) , a certificate of calibration from another participating institute in a second country is recognized as valid in the first country for the quantities , ranges , and measurement uncertainties specified in Appendix C of ferenc The activity and surface rate of Class 1 reference measurement standards shall be measured using , for example , a wi gas-flow proportional detector , or by using an instrument that been calibrated using that have been measured absolutely . Calibration procedures activity determination are discussed for example , in References [ 10 ] , ( 11 ) . [ 12 ] and [ 13 Organizations with a requirement to type test and to calibrate instruments to be used for monitoring radioactive surface contamination need to have access to suitable Class 1 or Class 2 reference measurement standards . The purpose of a working measurement standard is to check the calibration of surface contamination monitors in the field ; they are not to be confused with check sources , which are only intended to verify that a monitor is operating Organizations with a requirement to provide working measurement standards for the routine confirmation of the calibration of their surface contamination monitoring instruments require access to a reference transfer measurement device with which to calibrate such working measurement standards in terms of surface emission rate against a Class 1 or Class 2 reference measurement standard . Where e working measurement standard is used either in a jig or under a particular geometry , the reference transfer measurement device on which its emission rate is measured shall have been calibrated using a reference measurement standard under identical conditions and geometry . Alternatively , the working measurement standard shall be removable from the jig so that it can be measured in the usual way Where only a few monitors need calibration or a high degree of accuracy is required , Class 1 or Class 2 eference measurement standards may be used as working measurement standards . In such cases , the frequency...