金属管道腐蚀在线监测信号漂移的修正方法

Correction Method for Online Monitoring of Signal Drift in Metal Pipe Corrosion

针对石化行业中金属管道腐蚀的在线监测数据可靠性不高的问题,提出一种融合了场指纹技术(FSM)及电磁超声技术(EMAT)的检测方法。通过对FSM技术测量原理的理论分析,确定测量过程中数据误差的来源也就是失调电压的表达式,将FSM的测量结果与EMAT测量结果对比,将某一时刻EMAT的测量数据作为FSM数据的真值,得到修正后的探针电压值,从而修正了长期测量过程中因零点失调电压和数据处理单元放大倍数变化引起的测量数据漂移问题,实现对管道大范围、长期稳定的在线监测。实验结果表明:经过为期2 a的现场实际应用,所提出的数据修正方法将FSM测量数据的最大误差由修正前的10.09%减小到0.49%,最大误差减小了9.6百分点。

A detection method that could integrat field signature method(FSM) and electromagnetic ultrasonic transducer(EMAT) was proposed,aiming at the problem that the online monitoring data of metal pipe corrosion in the petrochemical industry was not reliable.Through the theoretical analysis of the measurement principle of FSM technology,the source of data error in the measurement process was identified,that was,the expression of offset voltage.The measurement results of FSM were compared with the measurement results of EMAT,and the measurement data of EMAT at a certain moment was taken as the true value of FSM data to obtain the corrected probe voltage value.Thus,the problem of data drift caused by zero offset voltage and data processing unit magnification change during long-term measurement was corrected,and the large-scale and long-term stable online monitoring of pipeline was realized.The experimental results showed that after two years of practical application,the proposed method could reduce the maximum error of FSM measurement data from 10.09% to 0.49%,and the maximum error was reduced by 9.6 percentage points.