| 摘要 |
PURPOSE:To enable an easy and accurate wide range monitoring with an automatic correction setting by detecting a switch point of both measuring circuits based on the counting of variation rates of the ratio between changes in the measured values by a pulse counting method corresponding to neutron flux level and those by the Campbel method. CONSTITUTION:According to the level of the detection value of a nuclear reactor output, a neutron flux measured value MSV or CPS is outputted by the pulse counting method with a counting rate measuring circuit 11 or by the Campbel method with a linear Campbel measuring circuit 13. A variation ratio coefficient DELTA of the ratio of variations in the measured values MSV and CPS is determined by computation according to the equation I with a digital arithmetic control section 13. The control section 13 detects a switch point based on a coefficient 1 which puts the measured value by the pulse counting method at the upper limit of making it linear to automatically switch the circuits 11 and 12 while the gain of a range switch amplifier 121 in the circuit 12 is automatically corrected. This enables an easy and accurate wide range monitoring of a neutron flux level or the like with a large range. |
