Electromagnetic flowmeter in the use process will produce some faults affect the normal work of the instrument, how to find the cause behind the fault is a very important work, we need to identify through a variety of different types of detection methods, in general, we for electromagnetic flowmeter routine testing, usually including electrode contact resistance, electrode polarization voltage, Signal cable interference, the determination of whether there is a grounding potential and the flow of stray current in the pipeline five aspects, these five aspects can be carried out separately, in fact, but also interrelated, any change in the factor may cause other changes, this reminds everyone in the detection of special attention: