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引言在射线测量中,常需对弱电流或电荷进行数字化的测量,例如:电离室、光电倍加管输出电流或加速器带电粒子束流等,其大小大约在10~(-14)A-10~(-5)A之间。常用的有下列两种方法: 其一是采用I-V变换电路,首先将电流转换成电压,然后再通过V-f变换,把电压转换成频率(脉冲),再把脉冲输入定标器加以记录。方块图如下所示:
Introduction In ray measurement, it is often necessary to digitally measure weak currents or charges, such as the ionization chamber, photomultiplier tube output current or accelerator charged particle beam, which is about 10 ~ (-14) A-10 ~ (-5) A between. There are two commonly used methods: One is the use of I-V conversion circuit, first of all the current into voltage, and then through the V-f conversion, the voltage is converted to frequency (pulse), and then the pulse input scaler to be recorded. The block diagram is as follows: