基于电导率测量的水纯度检测系统设计  

Design of Water Purity Detection System Based on Conductivity Measurement

作　　者：郭峰 崔永俊 韩一德 GUO Feng;CUI Yong-jun;HAN Yi-de(School of Instrument and Electronics,North University of China,Key Laboratory of Instrumentation Science&Dynamic Measurement,Ministry of Education,Key Laboratory of National Defense Science and Technology on Electronic Measurement,Taiyuan 030051,China)

机构地区：[1]中北大学仪器与电子学院,仪器科学与动态测试教育部重点实验室,电子测试技术国防科技重点实验室,山西太原030051

出　　处：《仪表技术与传感器》2021年第4期75-79,84,共6页Instrument Technique and Sensor

基　　金：国家自然科学基金资助项目(61335008)。

摘　　要：针对生活及工业中对水质纯度的需求,设计了一种基于电导率测量的水纯度检测系统。传感探头采用四环电极结构,可防止因为电极的电容效应和极化效应所带来的影响,提高准确度。探测头后侧金属壁内置Pt100温度传感器,进行温度采集和补偿。该系统用FPGA和AD9708实现波形频率可调输出,作为系统激励信号源。设计了差分电路接收传感器输出信号,并通过调理电路和滤波电路得到关键的幅值信息,通过A/D采集后传输给上位机,进行数据的分析处理。测试结果表明,该系统能够实时测量电导率,电导率测量的相对误差低于0.6%,具备较高的实用价值。Aiming at the demand of water quality purity in life and industry,a water purity detection system based on conductivity measurement was designed.The sensor probe adopted a four ring electrode structure,which can prevent the influence of electrode capacitance effect and polarization effect,and improve the accuracy.Pt100 temperature sensor was built in the metal wall at the back of the detector to collect and compensate the temperature.In this system,FPGA and AD9708 were used to realize the adjustable output of waveform frequency as the excitation signal source.The differential circuit was designed to receive the output signal of the sensor,and the key amplitude information was obtained through the conditioning circuit and the filter circuit,which was collected by A/D and transmitted to the upper computer for data analysis and processing.The test results show that the system can measure conductivity in real time,and the relative error of conductivity measurement is less than 0.6%,which has high practical value.

关 键 词：四环电极 PT100 电导率 调理电路 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]