| 摘要 |
PURPOSE:To make the statistical error of a digital rate meter constant by consturcting a closed loop of a frequency difference detecting circuit, an up- and down- counter and a pulse generating circuit so that feedback signals may follow pulse signals to be measured. CONSTITUTION:The disclosure is concerned with a rate meter for radioactive ray measurements. A closed circuit is constructed of a feruency difference detecting circuit 1, an up- and down-counter 2 and a pulse generating circuit 3. The pulse signals F1 to be measured and the feedback signals F2 from the pulse generating circuit 3 are fed differentially to the frequency difference detecting circuit 1 so that the up- and down-counter 2 generates the signals DELTAF indicating the frequency difference, the up signals indicating that F1>F2 and the down signals indicating that F2>F1. The circuit 3 generates the feedback signals F2 having such a frequency as is proportional to the integrated value of the counter 2. Thus, there can be generated at the output terminal D of the couter 2 the signals which are prepared by converting the pulse signals F1 into parallel digital signals.
|
