Patent ID: 8637827

Claim:
A radiation monitor comprising a sensor section and a monitor module section which are disposed separately from each other and connected to each other via a signal transmission path, wherein the sensor section comprises: a detection element that detects radiation and has sensitivity with respect also to light, a signal processing section that converts an output from the detection element into an electric signal for output, a light emitting element that irradiates the detection element with light, and a light emission control circuit that controls a pulse emission of the light emitting element occurring at a predetermined frequency, an on/off of the pulse emission, and an intensity of the pulse emission; the monitor module section comprises: a counter circuit section that counts a number of electric signals transmitted thereto from the signal processing section; a radiation amount calculation/display section that calculates a radiation amount from an output of the counter circuit section and displays a calculation result; an abnormality determination/display section that determines whether the output of the counter circuit section is an abnormal value and displays a determination result; a switching section that switches an output destination of the counter circuit section between the radiation amount calculation/display section and the abnormality determination/display section and transmits a determination result signal indicating that a sensor operation check mode is active to the light emission control circuit, the radiation amount calculation/display section and the abnormality determination/display section; a timer section that outputs a timing signal at a constant timing; and a sensor operation check mode determination section that determines whether the sensor operation check mode is active based on the timing signal of the timer section and an amount of radiation output from the radiation amount calculation/display section, and transmits the determination result signal indicating whether the sensor operation check mode is active to the switching section, the radiation amount calculation/display section, the abnormality determination/display section, and the light emission control circuit; and the signal transmission path transmits an output signal from the signal processing section to the counter circuit section and transmits a signal from the sensor operation check mode determination section to the light emission control circuit.