Double-flange level transmitter: large fluctuations
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Double-flange level transmitter: The diaphragm is in good condition, but the measurement values fluctuate up and down, showing instability. Operating conditions in industrial environments: temperature of 180–200 degrees, pressure of 0–40 KPA
Is it fluctuating up and down? Is the process stable?
Stable! It is that after using it for 3 months, this situation occurred
Isolate it first and see if it’s stable If it is stable, it is caused by the process; if it is unstable, it is caused by the transmitter side. Check to see if it is properly secured
If you confirm that the process conditions are stable, it seems there might be interference. It is possible to first disconnect the transmitter on-site and use a signal generator to send a signal to see if there are still fluctuations. Additionally, it is better to use the Hart handheld device to put the transmitter into loop test mode and apply a constant current value for observation.
The medium temperature is relatively high; in my opinion, this leads to significant fluctuations in the liquid level. You can close the valves on the upper and lower flanges of the transmitter to see if there are still fluctuations. If no fluctuations occur, it indicates a problem with the process; if fluctuations persist, it’s a problem with the transmitter itself. Additionally, interference such as electromagnetic interference can also cause fluctuations in the transmitter, so it’s worth checking that first.
It’s probably a process issue; the liquid level is unstable
It’s probably a process issue; the liquid level is unstable
If possible, it can be removed and pressure-tested to see if it remains stable, or it can be isolated for a while to observe the situation. The most likely reasons are that the installation location is not correct or that there are issues with the manufacturing process
The reasons need to be checked one by one, as mentioned above. However, such a range is relatively small; it is better to use a single-crystal silicon differential pressure level gauge. The influence of temperature on single-crystal silicon sensors can be ignored, and they offer good accuracy and stability over long periods of use. Traditional metal capacitive sensors suffer from significant temperature drift, especially with high-temperature media, and on top of that, their measurement range is relatively small!
——Shanghai Ligé 2880189604