工业上有时需要进行甚高电阻的测量。如果对这种电阻施加500伏电压,待测电流将是微微安数量级,可用一个先进的但也是相当昂贵的高输入阻抗的万用电表来测量。如果采用低电压,则这个电流就将太小,以致于无法用这种方法测量。目前,具有高输入阻抗和低偏置电流的现代的固体组件的存在,使得这种测量只要较少的费用就能实现。这是一种以运算放大器为基础的仪器,其指示仪是一只价 Industrial sometimes requires very high resistance measurements. If 500 V is applied to this resistor, the current to be measured will be on the order of Picoamps, which can be measured with an advanced but also quite expensive multimeter with high input impedance. With a low voltage, this current will be too small to measure in this way. Currently, the presence of modern solid components with high input impedance and low bias current allows this measurement to be achieved with less expense. This is an op amp-based instrument whose indicator is a price