电流环法测试管中电流技术应用

Application of the Swain Meter to Testing Currents in Pipeline

由于实际管道中阴极保护电流较小以及现场环境干扰严重,现有的方法难以测得真实的管中电流。文中结合现场案例,通过与电位差法作对比,介绍了电流环法在测量埋地管道管中电流方面的应用。结果表明:电流环法可以测量管道中电流的大小及方向;电流环法与电位差法测得的电流数值基本相同,但电流环法的测量值更稳定;由于地磁场对电流环的影响范围在±100 mA之内,当管中电流小于100 mA时,测试数值正负跳动,无法取值,也不能判断电流方向,电流环法不适用。

Because the real current of cathodic protection is so slight and that the surroundings have a serious interference,methods at hand can not meter the veritable current in pipeline. In this paper,combined with actual cases,a swain meter method is introduced to the application of testing the current in buried pipelines by comparing voltage difference methods. The results show that the swain meter is workable when used to measure the size and direction of a current in pipeline. The current values obtained by using the swain meter and the voltage difference method are basically the same. Moreover,the data tested by the meter is more stable. Due to the influence range of the magnetic field on the meter within ± 100 mA,the meter is not available when the tube current is less than 100 mA,because the testing value,positive or negative,and the size and direction of current cannot be determined.