基于场指纹法的金属管道小腐蚀坑的监测方法  

Monitoring method for small corrosion pits of metal pipeline based on field signature method

作　　者：甘芳吉[1] 万正军[1] 罗航[1] 宋康[1] 廖俊必[1] 

机构地区：[1]四川大学测控系,成都610065

出　　处：《仪器仪表学报》2013年第9期2087-2094,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(61271329);四川省科技支撑计划(2012GZ0094);四川大学青年基金(2011SCU11120)资助项目

摘　　要：FSM即场指纹法,是一种基于电位列阵的金属管道在线腐蚀监测的方法。该方法的核心在于将电极列阵分布在被测管道外部,利用电阻与管道厚度的关系,通过测量电极之间的电压来监测管道内壁的腐蚀情况。但是测量电极间的电压同时受腐蚀坑的面积和深度的影响,而一个电压值无法确定两个未知参数,故存在不可解问题。目前计算腐蚀坑的公式是将面积设定为固定值,由此得出的结果一般表现为坑的面积偏大而深度偏小,这也是当前FSM法最大的缺陷之一。在介绍FSM方法的基础上,针对传统FSM法对于小腐蚀坑的监测存在不可解问题,创新性地提出了一种综合利用主电压和辅电压来准确区分小腐蚀坑的面积和深度的方法。理论分析和实验表明,提出的主辅电压法可以大幅度提高小腐蚀坑的监测精度。The method of online metal pipe corrosion monitoring based on potential-array is also known as field signa- ture method （FSM）. The core of the method is monitoring the corrosion in the inner surface of the pipeline by meas- uring the voltages among the electrodes of the potential-array that is distributed on the outside surface of the metal pipeline using the relationship between the resistance and pipeline wall-thickness. While the voltages among the measuring electrodes are affected by the area and depth of the corrosion pit at the same time, thus there is no way to obtain two unknown quantities with only one known voltage. Currently, the formula for calculating the corrosion pits assumes that the area is a constant, which makes the area bigger, while the depth smaller; and this unsolvable problem can greatly improve the monitoring accuracy of the small corrosion pits.

关 键 词：场指纹法 腐蚀监测 小腐蚀坑 主电压 辅电压 

分 类 号：TH89[机械工程—仪器科学与技术]