1.1.1 This International Standard is applicable to installed, portable or transportable assemblies intended to measure ñ the direction of an X or gamma radiation source in terms of azimuth and elevation angles, as shown in the schema of figure 1; ñ the X or gamma air kerma rate at the equipment location; ñ the attenuation coefficient in a given medium and the related effective energy of the X or gamma beam incident to the equipment location. The energy range of X or gamma radiation is at least between 50 keV and 1,5 MeV. 1.1.2 The assemblies considered in this standard comprise at least ñ a detection sub-assembly which could include several detectors; ñ a measuring sub-assembly including a display device, which may be connected together or incorporated into a single assembly or interfaced. This sub-assembly could contain a microprocessor equipped with an algorithm to process the measured data. 1.1.3 This standard is applicable to measuring assemblies designed for special applications: e.g. high air kerma rate measurements and direction of the plume following a nuclear accident or, when mounted on a vehicle, to guide it towards the X or gamma sources and to bring it closer to the intervention place. 1.1.4 National regulation or practice may require the measurement of other quantities than air kerma rate (e.g. ambient dose equivalent rate, other dose rate or exposure rate). This standard may be applied to performance characteristics of equipment to measure any such quantity. For example, the numerical values given for the radiation characteristics apply to any case but the conventionally true values would be expressed in the appropriate quantity. 1.1.5 This publication specifies general characteristics, general test procedures, electrical, safety and environmental characteristics and the identification certificate for assemblies defined in this clause. 1.1.6 This standard does not apply to thermoluminescence dosimetry systems or other passive integrating devices. 1.1.7 This standard does not provide specifications for measurements of beta radiation and neutrons. 1.1.8 This standard is not applicable to the operating characteristics of indicating or recording equipments as such (e.g. indicating meters, recorders, alarms etc.). The characteristics of such equipment should be in conformity with the general requirements appropriate to them.