BS IEC 60846-2:2015 pdf download-Radiation protection instrumentation — Ambient and/or directional dose equivalent (rate) meters and/or monitors for beta, X and gamma radiation Part 2: High range beta and photon dose and dose rate portable instruments for emergency radiation protection purposes.
5 General characteristics of ambient dose equivalent (rate) meters for emergency purposes For the purposes of this standard, 5.1 to 5.1 4 of IEC 60846-1 :2009 apply, without modifications, except as stated in the following subclauses. The changed subclauses are identified by the same number as in IEC 60846-1 :2009 or, for new subclauses, by a higher number not used in IEC 60846-1 :2009. 5.2 Read-out Single scale is preferred. If multiple scales are used, the changing of measuring range and read-out scale shall be simultaneous and shall be clearly displayed. All scales shall be readable under normal lighting conditions. 5.3 Dose equivalent and dose equivalent rate range The implementation of ICRP recommendations requires the determination of dose equivalent rate over a wide range of values. Under some circumstances, dose equivalent rates as high as 1 0 Sv h –1 require measurement. For application as an emergency instrument, the dose equivalent rates of interest are within the range from approximately 1 mSv h –1 to 1 0 Sv h –1 . If integrating capability is provided, the range between 1 mSv to 1 0 Sv usually is of interest. 5.5 Minimum range of measurement The minimum effective range of measurement of dose equivalent rate shall cover at least four orders of magnitude and shall include the range from 1 mSv h –1 to 1 0 Sv h –1 . The minimum effective range of dose equivalent shall cover at least four orders of magnitude and shall include 1 0 Sv. 5.1 5 Portability In the case of survey meters, the complete instrument should not exceed 4 kg in weight and shall be equipped with handles, straps or other means to facilitate operation while being carried. It is recognized that an extension probe or some other means may be required to reduce the dose to the operator.