本文介绍了低纬子午环上电水准器的工作原理；讨论了电水准器在测定定位盘上盘的水平差时，其Ｄｅｔｉｃｏｎ的比例尺的测定方法及其测量精度；讨论了电水准器中狭缝倾斜量的测量方法；最后给出了水平差的测量范围以及可达到的精度，证明低纬子午环对轴系的要求是比较低的，而水平差的测量精度是相当高的。 This paper introduces the principle of low latitude meridian electrical level gauge; discusses the method and measurement accuracy of the Deticon scale when the electrical level gauge is used to determine the level difference of the disk on the positioning plate; Finally, the measurement range of horizontal difference and the achievable accuracy are given. It is proved that the requirement of low-latitude meridian ring on shaft system is relatively low, while the measurement accuracy of horizontal difference is quite high.