一、引言水准测量的施测精度,主要用水准导线测量的闭合差来表达。在讨论对排水管道施工水准测量精度要求之前,让我们先了解一下各有关标准对水准测量闭合差的规定。《国家水难测量规范》第3条规定,国家水准测量按控制次序和施测精度分为一、二、三、四等;又规定,三、四等水难测量直接提供地形图和各种工程建设所必须的高程控制点。第55条规定,三等水准测量闭合 I. INTRODUCTION The accuracy of the measurement of the level measurement is mainly expressed by the difference of closing measured by the level wire. Before discussing the requirements for measuring the accuracy of the construction of sewer pipes, let us first understand the requirements of the relevant standards for the poor closing of the leveling gauge. Article 3 of the “National Code for the Measurement of Water-Difficulties” stipulates that the national standard for leveling shall be classified into one, two, three, four, etc. according to the order of control and the measuring accuracy; and third, fourth and so forth, Engineering construction necessary elevation control point. Article 55 provides that third-level measurements are closed