由于直流比较仪式电位差计的价格昂贵及其在检定低电势电位差计时存在零漂和热稳定等问题,所以很多单位仍然采用元件检定电位差计的方法来检定标准电位差计。众所周知,高电势电位差计的元件检定精度可优于5ppm,经过这样检定的电位差计用作检定同级电位差计的标准是相当满意的了。但是,低电势电位差 Due to the high cost of the DC comparator potentiometer and the problems of zero drift and thermal stability when testing the low potential potential difference meter, many units still use the method of component verification potentiometer to verify the standard potentiometer. As we all know, high-potential potentiometer component verification accuracy can be better than 5ppm, after such a test of the potentiometer used to verify the standard of the same level of the standard is quite satisfactory. However, the potential difference is low