Measurement and application of high-value resistance

High-value resistance generally refers to the DC resistor with a resistance value of more than 1M or 10M which is widely used in electrometer, microammeter, insulation tester and other instruments, among which its stability is the key factor to determine the performance of instruments. Therefore, it is necessary to measure the temperature and voltage characteristics of high value resistance. The traditional bridge method can only measure high value resistance at low voltage. The paper demonstrates a measurement method for high value resistance, which is realized by a set of measurement device composed of multi-functional standard source and electrometer. It can meet both low voltage and high voltage conditions. This method is compared with the bridge method to measure the same high value resistance. It is concluded that the measurement method proposed in this paper is closer to the actual situation of high value resistance. At the same time, the paper analyzed effects of insulating materials, external electromagnetic interference, bending or vibration of the measurement cable, pollutants in the test environment on high resistance measurement, and puts forward some preventive measures to improve the accuracy of measurement It is suitable for the measurement of high-value resistance in general laboratories, and has practical application value.