Electromagnetic flowmeter output signal fluctuations in common causes

When the measured liquid flows normally and steadily in the smart electromagnetic flowmeter sensor measured on site, the signal output of the meter fluctuates greatly. The reasons are caused by the following three common reasons. Of course, there are many reasons for fluctuations. This article only lists three common ones. In other cases, users can refer to the product instruction manual.

1. The impact of external electrical and magnetic interference on the signal converter. There are many interference sources, including power interference (50hz power frequency interference), electromagnetic interference caused by motors, and common interference superimposed on the signal. Mode interference and so on. From the perspective of interference to the incoming signal converter, the main sources are power supply circuits and signal circuits. Converters generally return to normal when the source of interference disappears.

2. The impact of external interference on the sensor electrode of the smart electromagnetic flowmeter. When there is stray current in the sensor, there is an ionosphere attached to the electrode, or there is a large amount of interference signal on the signal line due to on-site grounding problems, the signal processing circuit will not be able to process the signal. Get the actual signal from the noise. When the liquid is a slurry containing many variable particles, and the particles in the liquid being measured wash away the electrode, a large number of interference signals will appear in the signal, and the signal processing circuit will also be unable to obtain the actual signal from the noise.

3. The smart electromagnetic flowmeter sensor is not full The tube state or the liquid contains bubbles. If an electrode is not in contact with the liquid being measured due to the above reasons, the signal on the electrode will be a messy signal. Intelligent electromagnetic flowmeter has high measurement accuracy. There are no flow obstructions in the measuring pipe, so there is no additional pressure loss.

Although the electromagnetic flowmeter has relatively good reliability and will not be damaged under normal circumstances, due to its principle, the sensor electrode surface is always in contact with the liquid. Over time, the electrode surface will More susceptible to contamination. Therefore, under normal circumstances, if the customer has the conditions to dismantle the electromagnetic flowmeter, it is recommended to disassemble it and clean the electrodes once every one to one and a half years to ensure the measurement accuracy of the entire flowmeter. Among the common problems of intelligent electromagnetic flowmeters, problems that occur during the trial operation phase are generally caused by installation problems or selection problems, while problems that occur during normal operation are generally caused by changes in working conditions or the emergence of new interference sources.

Therefore, problems during normal operation can generally be attributed to the anti-interference ability of the instrument. The faults of the smart electromagnetic flowmeter itself mainly refer to the faults of the instrument caused by the damage of components, while the faults caused by external reasons are mainly due to the pipe system and installation not meeting the requirements, the environment in which the instrument is used interferes with the instrument, and the measured liquid affects the flowmeter. Instrument failure caused by measurement interference and other conditions.