外径千分尺、游标卡尺、内径百分表是机械制造工业中使用最广泛的三大量具。其中内径百分表常用于测量孔径或内径尺寸。我们发现,有些工厂的工人不仅用内径百分表测量《公差与配合》中的3级和4级公差,而且还用于测量2级公差,测量时大都以外径千分尺作测量标准器,用其调整内径百分表的零位,再去测量工件尺 Micrometer OD, Vernier Caliper, ID Dial Indicator is the most widely used machinery manufacturing industry three measuring tools. Inner diameter dial indicator which is commonly used to measure the aperture or diameter size. We found that workers in some factories measured not only Grade 3 and Grade 4 tolerances in “Tolerances and Fits” with an inner diameter dial indicator but also Class 2 tolerances, most of which were measured with an outside diameter micrometer, Adjust the zero dial gauge, and then go to measure the workpiece