应用于腐蚀监测的金属探针阻值测量方法  

Measuring Method of Metal Probe Resistance Applied to Corrosion Monitoring

作　　者：王选择[1] 郑烨 张瑜灿 王浩伟 WANG Xuan-ze;ZHENG Ye;ZHANG Yu-can;WANG Hao-wei(School of Mechanical and Engineering,Hubei University of Technology,Wuhan 430068,China;China Special Aircraft Research Institute,Aviation Key Laboratory of Science and Technology on Structural Corrosion Protection and Control,Jingmen 448035,China)

机构地区：[1]湖北工业大学机械工程学院,湖北武汉430068 [2]中国特种飞行器研究所,结构腐蚀防护与控制航天科技重点实验室,湖北荆门448035

出　　处：《仪表技术与传感器》2022年第11期34-39,共6页Instrument Technique and Sensor

摘　　要：金属腐蚀探针由于本身的阻值很小,腐蚀过程中产生的阻值变化也十分微小。因此,通过阻值来反应腐蚀状况的实时监测方法要求很高的阻值测量分辨力,导致常规的测量方法难以满足要求。为此,设计了一种基于交流源驱动与自平衡补偿相结合的高精度阻值测量方法;采用STM32F407自带的数模转换模块(DAC)、运算放大器及三极管产生较大驱动能力的交流源并加载至金属探针与参考电阻,然后通过差分处理与自平衡补偿调节方法,完成高放大倍数的阻值检测,最终实现高分辨的腐蚀速率实时监控。实验表明:采用长度为0.1 m、直径为0.5 mm的金属丝,初始阻值为178 mΩ,均匀腐蚀条件下,其阻值分辨力达17.35μΩ,质量分辨力达30.24μg。The resistance of the metal corrosion probe is small, and the change of value varied little in the process of corrosion.Therefore, the method requires high resolution to real-time monitoring of reactive corrosion conditions by resistance, it is result in the requirement of the conventional method being difficult to meet.For this purpose, a high-precision measurement method of resistance was designed based on an ac source drive combined with self-balancing compensation.An ac source with greater driving power was generated by using a STM32 F407 digital-to-analog conversion(DAC),an operational amplifier and a triode to load into the metal and reference resistor.The resistance detection of the high magnification was completed by applying differential processing and self-balancing compensation adjustment.Finally, high resolution of the corrosion rate monitoring in real-time was realized.The experiment results show that the resolution of the resistance is 17.35 μΩ and the weight is 30.24 μg under uniform corrosion conditions by adopting the metal wire with a length of 0.1 m, a diameter of 0.5 mm and the initial resistance of 178 mΩ.

关 键 词：腐蚀监测 金属探针 双激励测量法 交流源 正弦拟合 自动平衡补偿 

分 类 号：TM933[电气工程—电力电子与电力传动]