This international standard is applicable to radiation meters and monitors designed for the direct measurement or the direct detection of surface communication by alpha and/or beta radiation emitting nuclides and which comprise at least: - a detection assembly (comprising counter tube, scintillation detector or semiconductor detector, etc) which may be connected either rigidly or by means of a flexible cable or incorporated into a single assembly. - a measurement assembly. Some meters and monitors consist of detection assemblies and measurement assemblies where it is possible to separate the detector assembly and use alternative detection assemblies. Confor