Research on Educational Practice to Realize Constant Measuring Force in Measurement with External Micrometer

Abstract

Although micrometer is a representative length measuring instrument, it is usually difficult for beginners to read the measuring value correctly because of its unique scale marking system. Therefore, the emphasis in the educational practice and training program of mastering micrometer was mainly put on how to read its scale. However, with the popularization of micrometers with digital displays, the scale reading becomes much less important. On the other hand, our comparison of measuring operations between skilled workers and beginners showed that the situation of contact between the micrometer′s spindle and the measured object seems more important than the scale reading itself. Particularly, the measuring force applied when the micrometer comes in contact with the measured object should always be constant, and the control of the measuring force has become an important skill for mastering the use of the micrometer. In this study, first an apparatus to measure the measuring force of the micrometer was developed. Then, the force applied by workers under different skilled levels was investigated by using this apparatus. Furthermore, related educational practice was conducted and the result showed that the developed apparatus was quite effective in measuring skill training.