Auto Mould,Auto Light Mould,Car Lamp Mould Pipe Fitting Mould CO.,Ltd , http://www.gosmould.com In production, we have encountered the measurement problem of the discontinuous three-division φ210_0~(+0.06)mm size as shown in Figure 1. Because it is a discontinuous three-division inner arc diameter, our factory does not have a three-point inner diameter micrometer directly. For the measurement, we used the method shown in Figure 2 to measure the diameter of the inner arc by controlling the value of h, and achieved good results.