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Electromagnetic flowmeter troubleshooting 5 methods

During the use of electromagnetic flowmeters, some faults will affect the normal operation of the appearance. For example, the factors that occur in the back of the fault are a very important task. We need to identify them through various types of viewing methods. Under normal circumstances, our view on electromagnetic flowmeters generally includes electrode touch resistance, electrode polarization voltage, signal cable disturbance, and determination of the presence or absence of ground potential and pipe stray current flow. These five aspects can be separate. Conducting, originally related to each other, any change in one element may lead to changes in other vendors, which suggests that we should pay special attention when viewing:
First, the electrode touch resistance measurement, electrode and liquid touch resistance value, can not directly remove the flow sensor from the pipeline and directly estimate the general condition of the juice electrode and the lining layer, which helps to analyze the factors.
Measuring the electrode and liquid touch resistance values can directly assess the general condition of the electrode and the lining layer without removing the flow sensor from the pipe, which helps to analyze the factors. Especially for the viewing of large-caliber electromagnetic flowmeters brings great convenience. This method can be used to measure the internal and external conditions of the flow sensor, such as whether the electrode and the lining layer have a buildup layer, the conductive layer is still of an insulating property, and the surface of the electrode is contaminated.
Second, the polarization voltage of the electrode Measuring the polarization voltage between the electrode and the liquid will help to determine whether the zero point instability or output sloshing is caused by the contamination or cover of the electrode. Use the digital multimeter 2V DC file to measure the polarization voltage between the two electrodes and the ground separately (the electromagnetic flowmeter can be tested without stopping the power, or it can be stopped). If the two measurements are nearly flat, the electrode is not contaminated or masked, otherwise the electrode is either contaminated or masked. The polarization voltage is determined by the "electrode potential" of the electrode material and the nature of the liquid. The measurement may range from a few mV to several hundred mV. Because in practice the two electrodes are not completely symmetrical in the contaminated condition, the voltage across the electrodes forms an asymmetric common mode voltage. The asymmetrical common mode voltage becomes a differential mode signal, forming a zero offset.
Third, the signal cable disturbance measurement signal cable is subject to external static induction and electromagnetic induction disturbance will make the electromagnetic flowmeter zero point change. In order to determine whether the zero point change is affected by the signal cable disturbing potential, it is necessary to determine the general size of the disturbance and the degree of influence on the electromagnetic flowmeter.
Fourth, determine the presence or absence of ground potential electromagnetic flow juice in normal use, such as sensor proximity (force) machine status changes (such as leakage), the ground potential will change and cause zero point change. Check whether there is any influence in this way. You can short-circuit the converter work ground C terminal and the maintenance ground G terminal, and determine whether there is a ground potential by changing the zero point (or the indicated value).
V. Pipeline stray current flow direction discrimination Sometimes the disturbance source for finding pipeline spurs is still in the downstream of the flow sensor to reduce the search scale and try to reduce or eliminate the influence of stray current disturbance.

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