| 摘要 |
PURPOSE:To obtain a discriminating circuit whose circuit scale is small, and which can change easily the upper limit and the lower limit of an energy discriminating level, by providing an A/D converter and a memory device on the circuit. CONSTITUTION:An energy signal (a) of a radiant ray which has been made incident on a radiation measuring instrument is converted to a digital signal (d) by an A/D converter 1, and outputted to a memory device 2. In the device 2, the digital signal (d) is used as an address and whether the energy signal (a) exists within a discriminating range or not is outputted. Accordingly, by this energy discrimination, an error caused by an influence of scattering is reduced. Also, since the device 2 which has stored a marker of an energy discriminating range is provided within a prescribed address range, and analog window comparator becomes unnecessary, by which a circuit scale can be reduced. Also, as for setting of an energy discriminating level corresponding to plural different radiation sources, it is possible to cope with by providing plural input/output ports on the device 2, and storing a marker of a different energy discriminating range at every input/output port.
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