基于双电极传感器的腐蚀电流检测系统抗扰技术  

Anti-disturbance Technology of Corrosion Current Detection System Based on Double Electrode Sensor

作　　者：岑远遥 刘聪[1] 万军[1] 贺琼瑶 何建新[1] 周俊 CEN Yuan-yao;LIU Cong;WAN Jun;HE Qiong-yao;HE Jian-xin;ZHOU Jun(Southwest Institute of Technology and Engineering,Chongqing 400039,China)

机构地区：[1]西南技术工程研究所,重庆400039

出　　处：《装备环境工程》2023年第8期142-151,共10页Equipment Environmental Engineering

摘　　要：目的针对金属电化学腐蚀中腐蚀电流检测,设计一种高精度I-V转换的微电流检测电路,突破宽范围微弱电流高精度检测技术。方法通过分析电路的稳定性,针对100 pA~10 m A的微弱腐蚀电流采集,采用法安级偏置运放实现I-V转换,设计基于ADG708电子开关的8档自动调节电路,并通过24位ADC实现高精度模数转换。针对微弱电流采集中信号易受噪声的影响,设计自适应滤波器用于信号滤波处理。结果通过MATLAB仿真自适应滤波器的有效性,结果表明,在采集i(k)=2sin(2πk)电流时,误差从0.29m A(1σ)降低到0.0039 mA(1σ)。通过电流源校准测试系统精度,在100 pA时误差最大,为4.7%;在10 mA时误差最小,为0.049%。当电流值低于100 nA时,测量误差可以控制在5%以内;100 nA以上时,测量误差可以控制在1%以内。结论在微弱电流采样中引入自适应滤波器后,系统的采样精度显著提高,突破了宽范围的腐蚀电流采集技术,实现了微弱电流检测。可以将腐蚀电流应用在金属腐蚀速率的评价中。The work aims to break through the high-precision detection technology of wide-range weak current and design a high-precision I-V conversion micro-current detection circuit for corrosion current detection in metal electrochemical corrosion.By analyzing the stability of the circuit,aiming at the acquisition of weak corrosion current of 100 pA~10 mA,the I-V conver-sion was realized with a normal safety bias operational amplifier,an 8-gear automatic adjustment circuit based on the ADG708 electronic switch was designed,and the high-precision analog-to-digital conversion was realized by 24-bit ADC;In view of the fact that the weak current collection signal was easily affected by noise,an adaptive filter was designed for signal filtering.The finiteness of the adaptive filter was simulated by MATLAB.The results showed that when collecting i(k)=2sin(2πk)current,the error was reduced from 0.29 mA(1σ)to 0.0039 mA(1σ);Through the current source calibration test system accuracy,the maximum error was 4.7%at 100 pA,the minimum error was 0.049%at 10 mA,the measurement error could be controlled within 5%when the current value was less than 100 nA,and the measurement error could be controlled within 1%when the current value was more than 100 nA.After the introduction of adaptive filter in weak current sampling,the sampling accuracy of the system is significantly improved,breaking through the wide range of corrosion current acquisition technology,and realizing weak current detection.It can be used in evaluation of the rate of metal corrosion through corrosion current.

关 键 词：双电极传感器 腐蚀电流 自适应滤波 信号调理 微弱电流采集 仿真 

分 类 号：TN721[电子电信—电路与系统]