Abstract: An apparatus for measuring neutrons and gamma rays is disclosed in which after pulses generated by neutrons are discriminated from pulses generated by gamma rays, two different counted values are obtained for either the pulses generated by neutrons or the pulses generated by gamma rays to control a discriminating circuit between the pulses by neutrons and the pulses by gamma rays so that a ratio between the different counted values is kept constant, and further two different counted values are obtained for either the pulses by neutrons or the pulses by gamma rays in a manner the same as the above-mentioned to control the output of a detector so that a ratio between the counted values is kept constant.

Abstract: A bulk material of grain, lump or any other form is irradiated with neutron and gamma radiation emitted from preferably a single radiation source, and preferably a single radiation detector detects the neutrons and gamma radiation transmitted through the bulk material, so that the moisture content of the bulk material can be accurately measured without being affected by the bulk density of the bulk material.