4、游标卡尺是由主尺与游标两部分组成的。主尺最小分格常为1 mm，游标上的分格通常取与主尺的M-1分格相当的长度分为M等分。若主尺上每一分格长度为 y mm，游标每一分格长度为 x mm, 那么y-x= The vernier caliper is composed of the main ruler and the vernier. The minimum division of the main ruler is usually 1 mm, and the partition on the cursor is usually equal to the length of the M-1 grid of the main ruler, which is divided into M-equal divisions. If the length of each division on the ruler is y mm and that of the cursor is x mm, th