一种消除分布电容影响的电阻测量方法  

A method of eliminating infection of distributed capacitance in measurement of resistance

作　　者：仲崇权[1] 兰敬辉[1] 杨素英[1] 

机构地区：[1]大连理工大学电子与信息工程学院,辽宁大连116024

出　　处：《大连理工大学学报》2003年第3期372-376,共5页Journal of Dalian University of Technology

基　　金：教育部优秀青年教师基金资助项目(教人司[2001]39号);国家"863"计划CIMS主题重点资助项目(2001AA413010).

摘　　要：提出一种变频电阻测量方法,选择两个合适频率的交流方波施加于由电极组成的分压电路上,测出分压电路输出精密整流滤波后的直流电压,通过解方程组求出分压电路时间常数τ,然后求得被测电阻值,这种方法有效消除了电容对电阻测量精度的影响.推导出了输出直流电压与被测电阻及电容之间的关系表达式.同时运用比例法有效地消除了交流方波幅值对测量精度的影响.实验结果表明,在分压电阻100kΩ下,电容在500～8000pF,被测电阻在1kΩ～1MΩ的测量精度小于1%.The paper proposes a changing frequency method which is able to measure the value of the resistance. First, two AC square waves that have appropriate frequency are imposed on the partial circuit which is made up of electrode; and then, the critically rectified DC voltage from the partial circuit is measured; and next, the time constant τ of the partial circuit is calculated by solving the equation set; at last, the value of the resistance is obtained. The method eliminates the infection of the capacitance effectively, which will affect the metrical precision of the resistance value. The connection expression between the output DC voltage and the resistance to be measured and the capacitance is derived in the paper. And the infection of AC square wave′s amplitude to the metrical precision is eliminated effectively with the proportion method. The experimental results indicate that the metrical precision can arrive within 1% in such a condition: the partial resistance is 100 kΩ, the capacitance is within the range of 500～8 000 pF, and the resistance to be measured is between 1 kΩ and 1 MΩ.

关 键 词：变频电阻测量 测量方法 测量原理 分布电容 比例法 测量精度 

分 类 号：TM934.1[电气工程—电力电子与电力传动]