Pertains to assemblies designed to measure the ambient dose equivalent (rate) due to neutron radiation in fields that contain neutrons with energies below 20 MeV, and which comprise at least: a) a detection assembly, which may, for example, consist of a detector probe for thermal neutrons and an arrangement of neutron moderating and absorbing media surrounding the detector; and b) a measuring assembly with a display for the measured quantity, which may be incorporated into a single assembly with the detector or connected to it by means of a flexible cable.