大内径小止口尺寸的测量方法一般如图1所示,主要同触头、转动杠杆和百分表组成测量工具。测量时,触头测值通过杠杆机构,再由百分表显示出来。当测量大内径小止口尺寸时,因触头较长,触头与止口接(?)较差,而杠杆机构又使测量误差加大,精度难以保证。 Big inner diameter of the small size of the mouth of the general measurement method shown in Figure 1, with the main contact, turn the lever and dial indicator form a measuring tool. Measurement, the contact measured through the lever mechanism, and then displayed by the dial indicator. When measuring small bore diameter large size, because the contact is longer, the contact with the mouth only poor (?), And the lever mechanism makes the measurement error increases, the accuracy is difficult to guarantee.