非侵入式差频电解质溶液电导率测量系统  

Contactless differential frequency electrolyte solution conductivity measurement system

作　　者：花一鸣 吴帅 张军 朱建平[1] 吕春峰[1] Hua Yiming;Wu Shuai;Zhang Jun;Zhu Jianping;Lyu Chunfeng(School of Engineering Science and Technology,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]上海海洋大学工程学院,上海201306

出　　处：《电子测量与仪器学报》2025年第2期231-239,共9页Journal of Electronic Measurement and Instrumentation

摘　　要：针对传统接触式电解质溶液电导率测量中存在测量电极被极化、被测溶液易受污染等问题,提出一种基于电涡流效应的非侵入式双线圈电解质溶液电导率测量系统。通过建立有限元分析模型,深入探讨了激励频率、线圈几何参数等对测量系统灵敏度的影响,为系统探头设计以及误差分析提供了理论基础。实验部分,优化了线圈探头参数,搭建了基于FPGA的双线圈差频式测量系统,该系统能够将电感变化转换为频率变化,实现数字信号输出。双线圈由检测线圈和参考线圈组成,其中检测线圈用于测量被测溶液,参考线圈远离被测溶液且仅受环境影响,二者信号实现差动输出,可消除外界干扰。对比实验显示,该系统能有效测量不同电导率溶液,验证了仿真模型的正确性。进一步的温度和抗干扰实验表明,双线圈差动结构在确保测量精度的同时,显著增强了系统的抗干扰性能,整体误差控制在1.2%以内,展现了该系统的实用性和可靠性。Aiming at the problems of polarization of the measuring electrode and contamination of the measured solution in the traditional contact electrolyte solution conductivity measurement,a non-invasive double-coil electrolyte solution conductivity measurement system based on eddy current effect is proposed.Through the establishment of a finite element analysis model,the effects of excitation frequency and coil geometry parameters on the sensitivity of the measurement system are discussed in depth,which provides a theoretical basis for the design of the system probe as well as the error analysis.In the experimental part,the coil probe parameters are optimized,and the FPGA-based dual-coil differential-frequency type measurement system is built,which is capable of converting inductance changes into frequency changes and realizing digital signal output.The dual-coil consists of a detection coil and a reference coil,in which the detection coil is used to measure the measured solution,the reference coil is far away from the measured solution and is only affected by the environment,and the signals of the two are realized as differential outputs,which can eliminate external interference.Comparison experiments show that the system can effectively measure different conductivity solutions,which verifies the correctness of the simulation model.Further temperature and anti-interference experiments show that the dual-coil differential structure significantly enhances the antiinterference performance of the system while ensuring the measurement accuracy,and the overall error is controlled within 1.2%,which demonstrates the practicality and reliability of the system.

关 键 词：非侵入式 电涡流 双线圈 差频 电导率测量 

分 类 号：TN98[电子电信—信息与通信工程]