| 摘要 |
PURPOSE:To measure a detection signal even during calibration and to monitor the operation of a nuclear reactor all the time by calibrating the detection signal from a detector on on-line basis while monitoring the signal. CONSTITUTION:Changeover switches 3, 15, and 23 are placed in signal measurement states as shown in a figure to measure the detection signal from an input terminal 1. Movable terminals (c) of the switches 15 and 23 are switched to fixed terminals (b) during the calibration to add a calibration signal from a calibration signal generator 13 to the detection signal from the terminal 1 through a resistance 17, and the sum signal of the calibration signal and detection signal is measured by a measuring circuit 5. A measured value from the circuit 5 is applied to one input of a subtracter 21, which subtracts the calibration signal value of a DC power source 25 for calibration. Then, only the detection signal is outputted from the subtracter 21 and supplied to a trip circuit 7 and an indicator M. Then, the error of the circuit 5 is calculated from the difference between the detection signals before and after the switches 15 and 23 are operated to perform the calibration, and the detection signal is supplied even during the calibration and monitored. |
