| 摘要 |
PURPOSE:To efficiently discriminate between a particle signal and noises and to improve S/N by providing 1st-3rd comparing circuits, a differentiating circuit, a timing generating circuit, 1st and 2nd storage circuits, etc. CONSTITUTION:The 1st comparing circuit 2, the 2nd comparing circuit 3, the 3rd comparing circuit 8, differentiating circuit 6, timing generating circuit 10, the 1st storage circuit 13, the 2nd storage circuit 14, etc., are provided. The circuit 2 compares a potential difference V with a 1st predetermined threshold value Q to generate an output (c) and the circuit 3 compares the potential difference V with a 2nd predetermined threshold value U to generate an output (d); and the circuit 6 differentiates the potential difference V to output the differentiated value and the circuit 8 compares the differentiated value D with a 3rd threshold value Z to generate an output (e). The circuit 10 is actuated in response to the variation of the output (c) of the circuit 2 from V<Q to V>Q to set the start point t=0 of time, and clocking operation is started at this point to generate the 2nd timing signal T2 and the 1st timing signal T1 longer than it. Further, a decision circuit 15 outputs a particle detection signal PSIonly when the contents of the output (h) of the circuit 14 indicate Z>D.
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