| 摘要 |
PURPOSE:To achieve accurate detection of abnormal counting and erroneous counting by determining abnormality from a difference or an error between acutual counts and the maximum or minimum value which was only memorized for respective time intervals beforehand. CONSTITUTION:Particles pulse signals from a line 13 are sent to shift registers 1 and 3. A signal for starting the counting is inputted to a line 14 while a signal for ending thereof into a line 15. On the other hand, a clock pulse generator circuit 11 generates pulses at specified time intervals set by dividing the counting time and actuates comparators 5 and 6 to compare counts of shift registers 1 and 2 and 3 and 4 and the register 2 memorizes the maximum value of the counts while the register 4 the minimum value. The clock pulses also reset the shift register 1 and 3 through a delay circuit 12. Based on the counts thus obtained, a subtraction circuit 7, a division circuit 8 and an abnormality discrimination circuit 9 are actuated after the end of the counting and an alarm 10 starts to work when any count exceeds the limit. |
