一种修正自发电动势的液体电导率测量方法  

A liquid conductivity measurement methodby correcting spontaneous electromotive force

作　　者：陈艺婷 倪浚皓 卢浩楠 黎语晨 董仕练 CHEN Yi-ting;NI Jun-hao;LU Hao-nan;LI Yu-chen;DONG Shi-lian(School of Electrical and Automation,Wuhan University,Wuhan,Hubei 430072,China;School of Physical Science and Technology,Wuhan University,Wuhan,Hubei 430072,China)

机构地区：[1]武汉大学电气与自动化学院,湖北武汉430072 [2]武汉大学物理科学与技术学院,湖北武汉430072

出　　处：《大学物理》2024年第7期74-80,共7页College Physics

基　　金：武汉大学实验技术项目(WHU-2021-SYJS-0004、WHU-2023-SYJS-0015);武汉市知识创新专项曙光计划项目(2023020201020263);国家自然科学基金青年科学基金项目(12304046)资助。

摘　　要：本文提出了一种基于电桥平衡原理的新型液体电导率测量方法.液体的电阻由于常规测试过程中其自身电容性和自发电动势的干扰,会导致电导率测量的不准确性.本文以高频交流电代替直流电,减弱电容的干扰,以示波器替换检流计优化电桥平衡判断标准,即以示波器显示非零直线信号为基准判断电桥平衡.基于此可探究并发现硫酸钠溶液浓度与其电导率呈线性相关,相对不确定度可低至1.8%,该结果可成功用于未知溶液浓度和模拟降雨量的双盲预测.A novel liquid conductivity measurement method based on the principle of bridge balance is proposed.The accuracy of conductivity measurement is affected by inherent capacitance and spontaneous electromotive force of liquid,which are encountered in conventional testing processes.To mitigate the interference caused by capacitance,high-frequency alternating current is employed instead of direct current.Additionally,an oscilloscope is used as a replacement for a galvanometer optimizes the criteria for bridge balance determination.Specifically,the oscilloscope indicates a non-zero linear signal as the reference for bridge balance.Based on this method,it is observed that the concentration of sodium sulfate solution exhibits a linear relationship with its conductivity.The relative uncertainty can be reduced to as low as 1.8%.This finding can be successfully applied in blind predictions of unknown solution concentrations and simulated rainfall amounts.

关 键 词：液体电导率 平衡电桥 电动势 电容性 

分 类 号：O4-34[理学—物理]