在工程质量监督检查部门的日常工作中,经常会遇到多种多样的不定跨度需要检测,目前大都采用“手拉钢尺法”来完成。这种办法的测得值误差较大,故其测量结果是不准确的。例如对同一跨度,即使由同一个人进行多次测量或由几个人同时进行测量时,其测量结果也难以保证完全一致。这种情况都是因为手的拉力不知大小,故其测量误差亦因之不得而知,从而也就无法将误差计入测得值之中。再如当安装尺寸偏大时,可将钢尺拉紧些,测得的尺寸就小些;当安装尺寸偏小时,可将钢尺拉松些,测得的尺寸就大些。由于上述情况的存 In the daily work of the engineering quality supervision and inspection department, there are often a variety of uncertain spans that need to be inspected. At present, most of them use the “hand pull rule” method. The error of the measured value of this method is large, so the measurement result is inaccurate. For example, for the same span, even if the same person makes multiple measurements or when several people measure simultaneously, the measurement results are difficult to guarantee complete consistency. This situation is due to the fact that the hand’s pulling force is not known, so its measurement error is also unknown, and thus it is impossible to count the error into the measured value. Another example is when the installation size is too large, the steel rule can be tightened, the measured size is smaller; when the installation size is small, the steel rule can be loosened, the measured size is larger. Because of the above situation