零级检验角尺测量面的垂直度偏差,可视工作部分的长度不同在2.5～4.4″范围内变化。根据文献[2],这类角尺的检定工作是与同级精度的标准角尺进行比较实现的,而且标准角尺必须用高精度的特种仪器进行检定,如用ГС-1M 型测角仪之类的仪器来检定,但这类仪器在各工厂企业中一般都不具备。苏联沃龙涅什市生产联合组织的М.И.加 Zero-degree inspection angle measuring surface of the vertical deviation, the length of the visual part of the work in the 2.5 ~ 4.4 "range changes.According to the literature [2], this type of square ruler is compared with the standard of the same level of accuracy to achieve , And the standard square must be calibrated using a high-precision special instrument such as the Gamma-1M goniometer, but such instruments are generally not available in various plant enterprises. City Production Joint Organizations М.И. 加