Range selecting apparatus of intermediate output monitor for nuclear reactor

Object: To avoid unnecessary scrum by alleviating the burden of range selecting by an operator and eliminating errors in the range selection. Structure: The apparatus comprises an intermediate output monitor for detecting the neutron flux within the reactor and determining the neutron flux value of an intermediate output system through an amplifier having a switching range and a wide range of amplification degrees, a plurality of recording sections for recording a neutron flux value obtained by the monitor, and a computer for receiving said neutron flux range value and started by a range selection demand signal for setting the range position according to the neutron flux value. The preset signal for the range position is used to effect range selecting of the switching range and the degree of amplification of the amplifier, whereby a recording section suited to the neutron flux value is selected for recording. (Kamimura, M.)