一、前言目前自动电子电位差计(以下简称为自动电位差计或仪表),在我国的各个工业部门和科研单位中应用相当广泛。但常遇到一部分本来正常工作的仪表,一装到现场中使用就失灵了,如出现误差增大、灵敏度下降、变差增大等现象。特别是与热电偶配套工作的仪表,用来测量和调节电炉、盐浴炉温时,情况更为严重,甚至使指针来回摆动或不稳定,以致无法工作。仪表在使用中产生失灵现象的原因很多,有些是由于仪表质 I. Introduction At present, the automatic electronic potentiometer (hereinafter referred to as automatic potentiometer or meter) is widely used in various industrial departments and research institutes in our country. But often encounter some of the instruments have been working properly, installed on the scene to use the failure, such as error increases, the sensitivity decreased, the increased variation and so on. Especially with thermocouple supporting the work of the instrument used to measure and regulate the electric furnace, salt bath furnace temperature, the situation is more serious, and even make the pointer back and forth swinging or unstable, so can not work. There are many reasons for the failure of the instrument in use, and some due to the instrument quality