| 摘要 |
The operation of a radiation detector arrangement (1) for ionising radiation is to be continuously checked in its switched-on state, without using a test radiator and without measures to be taken by an operator. For this purpose, the constantly present zero-point radiation is used. The monitoring arrangement (55) is connected in parallel with the normal measuring circuit (2) to the output (15) of the radiation detector (4). It contains a simple pulse generator (56) followed by a pulse shaping stage (57), the output pulses of which are counted in an electronic counter (58). The reset input (61) of the counter is connected to the output of the radiation detector so that the counter is reset with each pulse of the detector. The maximum count of the counter at which an output signal is output to a following alarm device (14) is selected in such a manner that the product of the duration of the period of the generator signal and of the maximum count is greater by a multiple than the mean pulse-to-pulse spacing of the output pulses of the radiation detector caused by the zero-point radiation. <IMAGE>
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