一种微小电阻测试系统的设计  

The design of a micro-resistance test system

作　　者：段雯[1] DUAN Wen(Xi an Jiaotong University City College,Department of Electrical and Information Engineering,Shaanxi Xi an 710018,China)

机构地区：[1]西安交通大学城市学院电气与信息工程系,陕西西安710018

出　　处：《工业仪表与自动化装置》2023年第1期26-30,共5页Industrial Instrumentation & Automation

摘　　要：为了精确测试微小电阻,基于开尔文四线检测法,设计了一种精度较高的微小电阻测试系统。设计方案为:微小电阻施加稳定恒流源信号后,通过采用AD8221为核心的一级放大电路、巴特沃斯二阶有源低通滤波和二级放大电路,获取放大、去噪、平稳的电压信号,经由ADC采集转换后显示被测电阻的阻值。采用最小二乘法拟合曲线对系统测试数据进行误差分析,显示误差小于0.2%,表明该系统测量精度高,可用于精准测量微小电阻以及微弱信号调理放大的场合。In order to accurately test the micro-resistance,based on the Kelvin four-wire detection method,a high-precision micro-resistance test system is designed.The design scheme is:after applying a stable constant current source signal on the tiny resistor,the first-stage amplifier circuit with AD8221 as the core,the Butterworth second-order active low-pass filter and the second-stage amplifier circuit are used to obtain amplification,denoising,and smoothness.The voltage signal is collected and converted by the ADC to display the resistance value of the measured resistor.The least squares fitting curve is used to analyze the error of the system test data,and it shows that the error is less than 0.2%,indicating that the system has high measurement accuracy and can be used for precise measurement of small resistances and weak signal conditioning and amplification occasions.

关 键 词：微小电阻测试 开尔文四线检测法 微弱信号 最小二乘法 

分 类 号：TM932[电气工程—电力电子与电力传动]