Applicable to all portable assemblies designed to measure the ambient dose equivalent rate due to neutron radiation of energy up to 16 MeV, and which comprise at least: - A detection sub-assembly, which may consist of a detector probe and a moderating and absorbing medium surrounding the detector; - A measuring sub-assembly, which may be incorporated into a single assembly or connected by means of a flexible cable; - If these assemblies are to be used in pulsed fields, it is strongly recommended that the user determines that under the conditions concerned, the assembly can operate correctly. - The purpose of it is to lay down performance requirements and methods for the assessment of portable neutron ambient dose equivalent rate meters.