Reasons and solutions for time tube alarm when using electromagnetic flowmeter

NegotiableUpdate on 03/21

Model

Nature of the Manufacturer: Producers

Product Category

Place of Origin

Online Consult

Overview

In general pipeline fluid measurement, electromagnetic flow meters can only measure unidirectional fluids. If the direction of the fluid changes, the measurement cannot be carried out. There are not many flow meters that can measure bidirectional flow. Normally, we know of electromagnetic flow meters and ultrasonic flow meters. The forward and reverse flow directions of electromagnetic flow meters can be set. When installing horizontally, flow selection provides a lot of convenience for the site. But when installed vertically, the fluid can only pass through the flowmeter from bottom to top. The electromagnetic flowmeter has strict requirements for full pipe. When the fluid passes through the flowmeter and does not meet the full pipe requirement, the flowmeter will sound an empty pipe alarm and the meter head will display no flow.

Product Details

Electromagnetic flow meters often encounter empty tube alarms during use. The so-called empty tube alarm of electromagnetic flow meters refers to detecting whether the measured fluid is filled with the sensor measuring tube and detecting the cause of the empty tube alarm. We can short-circuit the converter signal input terminal and ground three points with wires. If the measurement result shows that the empty tube becomes full, it indicates that the converter of the electromagnetic flow meter is normal. The cause of the malfunction may be low conductivity of the measured fluid or incorrect setting of the empty tube threshold. In addition, if there is a problem with the electrode of the electromagnetic flowmeter, there may also be a situation of air traffic control alarm

When the electromagnetic flowmeter triggers an air traffic alarm, the following measures should be taken:

1. Measure whether the fluid is filled in the measuring tube;

2. Connect the converter signal to terminals SIG1, SIG2, and SIGGDN with wires to short-circuit them. If the "empty tube" prompt is cancelled at this time, it indicates that the converter is normal. It is possible that the conductivity of the measured fluid is low or the threshold and range of the empty tube are set incorrectly;

3. Check if the signal line connection is correct;

4. Check if the sensor electrodes are normal;

5. Set the flow rate to zero and observe that the conductivity ratio should be less than 100%;

6. In the presence of current, the resistance of terminals SIG1, SIG2, and SIGGDN should be less than 50k Ω when measured separately.

7. The DC voltage between DS1 and DS2 measured with a multimeter should be less than 1V. Otherwise, it indicates that the sensor electrode is contaminated and should be cleaned.