| 摘要 |
<p>PURPOSE:To step up sensitivity by detecting even low-level signals and restrict the effect of a pulse interval measurement valve due to variation in rising and falling times. CONSTITUTION:A pulse width calculating circuit 40 is so constructed that signals passing through the first threshold testing circuit 21 may be all deemed effective and signals which have a specified-extent pulse width out of signals passing through the second threshold testing circuit 22 only which has a lower threshold may be only deemed effective. Rising and falling times at constant levels relative to peak levels are detected to find the central point by using a central point calculating circuit 41 and calculate a pulse interval from the central point by using a pulse interval calculating circuit 42.</p> |
