微弱电离电流测量方法的比较

Comparison of Three Kinds of Weak Current Measurement Methods in Ionizing Radiation

为了在实验中可以对静电计直接测量法和高增益负反馈法及汤森零位补偿法更好地使用,用这3种方法分别对监督源中电离室的电离电流进行了多次重复性测量,测量结果显示,静电计直接测量法对微弱电流的测量不确定度较大,而后两种绝对测量方法的相对不确定度则较小,所以在测量微弱电离电流时,对于不同的不确定度要求可根据实际情况选择合适的方法进行测量.

In order to better use direct electrometer measurement,high gain negative feedback absolute measurement method and Thomson zero compensation method to measure in the experiment,the three methods were used to measure the ionization current of the ionization chamber in the monitoring source repeatedly.The measurement results show that the uncertainty of the measurement of the weak current is larger with direct electrometer measurement,the relative uncertainty of the measured values of the two later methods is smaller,so when measuring the current,the relative uncertainties are different.According to the actual situation,it should be to choose the appropriate method for measurement.