The electromagnetic flowmeter’s tube is empty; the gauge shows flow, but it is unstable.
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There is an electromagnetic flowmeter on site; when there is no flow, the gauge reading keeps fluctuating, and at times it reaches the full scale. During normal feeding, the flow meter shows normal readings. Settings such as air traffic control alarms have also been configured in the table header, and parameters like instrument coefficients are normal. I wonder if any experts have encountered this problem as well; I’d appreciate some advice!
Is grounding done? Check the grounding ； There seems to be a function called resetting the air traffic control settings; if it exists, turn it on
I’ve encountered it before: the electrodes got clogged with dirty substances. . . It can’t be detected without checking the table. . .
The grounding was done properly, as it is quite important for electromagnetic flowmeters to have proper grounding; therefore, the grounding was carried out correctly at that time. I haven’t seen the function to reset air traffic control yet; I’ll go and give it a try on site later. Thank you
Well, I also considered the possibility that the electrodes were dirty. At that time, Party A was unwilling to disconnect the meter. Wait until I park and check the meter. Thank you
When the electromagnetic flowmeter is in empty-tube mode, the detection function doesn’t work properly!
You need to understand the principle of the device. The so-called \"open circuit\" state requires calibration – that is, calibration is carried out when the meter is indeed in an open circuit state and the meter itself is functioning properly. The purpose of this calibration is to establish a baseline value for the voltage generated at both ends of the electrodes; this value is then defined as the open circuit state. You say that it functions normally when there is water present, but this notion of normality is merely your guess. Who knows whether it’s actually normal or not? If you want to determine whether something is truly functioning properly, you need to obtain data from the manufacturer – such as the internal resistance of the excitation coil, the excitation voltage, the excitation current, and also the flow rate corresponding to that excitation voltage during factory calibration. Only in this way can you tell whether it is working properly or not. If there are discrepancies between the actual performance and the original data, it indicates that there is a problem with the instrument. If you are using a tubular electromagnetic flowmeter, cleaning the electrodes poses a challenge; without a bypass, production must be halted.
Thank you, I’ll give it another try when I get there. Thank you!
During air traffic control, the readings were abnormal; however, it should output 4 ma. The gauge’s reading shouldn’t fluctuate.
In an electromagnetic flowmeter, two coils are arranged radially to generate a magnetic field. The conductive fluid fills the pipe and flows, cutting through the magnetic field lines to produce an induced voltage, which is then converted into a 4–20 mA current signal. When the pipe is not filled with fluid, a multiphase flow exists within it, and electromagnetic induction is uncertain. Air traffic control is not a normal operating condition for electromagnetic flowmeters, so the gauge display is unstable. Some models of electromagnetic flowmeters have a blank pipe detection function, which issues an alarm when a blank pipe is detected.