一、问题的提出过去甚至直到现在,大部纷工厂是根据经验来选择计量器具的,通常选择计量器具的测量极限误差约占工件公差的1/3～1/5(或1/3～1/(10)),对于一些高精度工件,甚至有取1/2的。这样,就没有一个统一的标准。不仅如此,而且大多数工厂检验工件时,均按图纸上标注的极限尺寸作为验收极限。这种验收极限与工件的极限尺寸重合的方法,由于计量器具内在误 First, the problem raised In the past or even now, most factories are based on experience to choose measuring instruments, measuring instruments usually choose the ultimate error of about 1/3 ~ 1/5 of the workpiece tolerance (or 1/3 to 1 / (10)), for some high-precision workpiece, and even take 1/2. In this way, there is no single standard. Not only that, but most of the factory inspection of the workpiece, according to the drawings on the limit size as the acceptance limit. This limit of acceptance and limit the size of the workpiece coincidence method, due to internal errors in measuring instruments