News

Flowmeter manufacturer's common fault-focused microfluidic control technology in debugging

I. Failure during the debugging period
1) Fluids
The measured liquid contains evenly distributed microbubbles that usually do not affect the normal operation of the flowmeter. However, as the air bubbles increase, the output signal of the instrument will fluctuate. If the air bubbles are large enough to cover the entire surface of the electrode, the air bubbles flow through. Electrode will momentarily open the electrode circuit and cause greater fluctuations in the output signal
2) Environmental aspects
The stray current interference of the pipeline usually achieves a satisfactory result by adopting a good individual grounding protection. However, if a strong stray current is encountered, additional measures must be taken to insulate the flow sensor and the pipeline. Space electromagnetic interference is generally introduced via signal cables and is usually protected by single or multiple layers of shielding.
3) When the electromagnetic flowmeter with low-frequency square wave excitation measures the solid content of too much slurry, it will also generate slurry noise, which will cause the output signal to fluctuate. When measuring mixed media, if you enter the flow sensor for measurement before the mixing is not uniform, the output signal will also fluctuate.

Second, the operating period failure
The fault in the running period is the fault that occurs after the flowmeter manufacturer has been commissioned and is in normal operation for a period of time. The common faults during the running period are generally caused by factors such as the adhesion layer on the inner wall of the flow sensor and lightning strike.
1) Lightning strike
Lightning strikes easily induce high voltages and surge currents in the flowmeter circuit, causing damage to the flowmeter. It is mainly introduced through the power line or the excitation coil or the flow signal line between the sensor and the converter, and is particularly introduced from the control room power line.
2) Sensor inner wall adhesion layer
Since the flowmeter is commonly used to measure dirty fluids, after a period of operation, the adhesive layer often accumulates on the inner wall of the sensor to cause a malfunction. These failures are often caused by the electrical conductivity of the adhesion layer being too large or too small. If the attached material is an insulating layer, the electrode circuit will be broken, and the flowmeter will not work normally; if the electrical conductivity of the adhesive layer is significantly higher than the fluid conductivity, the electrode circuit will be short-circuited and the flowmeter will not work normally.

PREVIOUS：Natural gas flow meter error and elimination NEXT：Application of Gas (Natural Gas, Steam) Flowm