在万能工具显微镜或一般工具显微镜上用影象法或轴切法测量圆锥螺纹中径是简便易行而且精度较高的方法,因而被广泛采用。但此法本系圆柱螺纹的测量方法,用于圆锥螺纹有一理论误差存在。对该误差的处理,目前诸文献上说法不一:有的文献避而不谈这个问题,略去了此项误差;另一些文献指出精密测量时应作修正,可是介绍的修正量计算公式不仅形式不同而且符号相反。此种情况使计量检验人员工作时无所适从。因此,有必要对这个问题深入进行探讨。 In the universal tool microscope or general tool microscope image method or axial cutting method to measure the taper thread diameter is easy and accurate method, which is widely used. However, this method is based on the method of measuring cylindrical threads for taper threads which have a theoretical error. The treatment of this error, the current literature on different arguments: Some literature to avoid this problem, omitted the error; Other literature pointed out that precision measurement should be amended, but the introduction of the correction formula is not only not only Different forms and opposite signs. This situation makes metrology inspectors work at a loss. Therefore, it is necessary to discuss this issue in depth.