欧姆表测量原理和倍率的探讨

Discussion on Measuring Principle and Magnification of Ohmmeter

欧姆表的应用属于高考必考热点实验之一,但关于欧姆表的诸多问题,如刻度线特点的理解、测量系统误差分析等,无论是一线物理教师还是高考考生只知其然而不知其所以然,关于欧姆表的测量原理和换挡原理更是欧姆表的难点,而教材和各种教辅资料对该类问题都没有系统地解释说明.本文结合闭合电路欧姆定律等知识,将欧姆表的问题进行深入研究.

The application of an ohmmeter is one of the compulsory experiments for the college entrance examination.However,whether frontline physics teachers or college entrance examination candidates,they only know the characteristics of ohmmeters,such as the characteristics of scale lines,measurement system error analysis,and so on,but don′t know why.The measurement principle and shifting principle of an ohmmeter are even more challenging,and there is no systematic explanation of these issues in textbooks and various teaching aids.In this paper,combined with the knowledge of closed circuit Ohm's law,the problem of ohmmeter is deeply studied.