Common pressure transmitter fault types and solutions

1. The pressure display value is abnormal.

Abnormal pressure value display is a common fault of pressure transmitters UPB13. In addition to common zero point drift and range migration problems, the causes include component damage, sensor failure, wiring failure, electromagnetic interference, and pressure induction tube/ Capillary problems, etc. These problems need to be investigated one by one.

2. The components are damaged.

It is necessary to consider whether there is a short circuit or open circuit caused by excessive lightning strike voltage, incorrect wiring or damaged cables. If it is verified that any electronic components have been burned or physically damaged, the damaged components or cables must be replaced in time, and the instrument grounding system must be checked and maintained in a timely manner. Pay attention to whether water has entered the instrument, causing corrosion of internal electronic components. If the cable interface is not tightly sealed and the transmitter sealing ring is aging, it is easy to cause water to accumulate inside and outside the meter, leading to damage to the internal components. At this time, damaged components should be replaced, and the transmitter should be sealed and inspected.

3. Sensor failure.

For diaphragm pressure transmitters UPB2, medium crystallization will condense on the diaphragm, or the medium contains massive solids that impact the diaphragm for a long time, causing deformation and damage to the diaphragm and affecting measurement. At this time, the diaphragm should be replaced in time, and according to the actual working conditions, consider adding purge or adding a filter at the front end.

4. Wiring failure.

Wiring faults are generally caused by internal wiring, and can be checked by using a multimeter to measure resistance and voltage. Perform wiring operations according to the transmitter instructions to ensure the correct connection of the wires.

5. Electromagnetic interference.

This kind of fault is generally difficult to troubleshoot, but it occurs very frequently. The signal cable of the instrument should be avoided to be close to the electrical high-voltage signal cable. Otherwise, signal interference will easily occur, causing communication errors, inaccurate measurement values and other problems. Be sure to follow the standard requirements for distance control and shielding measures. The pressure transmitter UIB6 should also be installed away from locations with strong magnetic/electric fields or strong vibration sources.

6. Problem with pressure tube or capillary tube.

Problems with the pressure tube usually occur due to the characteristics of the medium, non-clean media, or media with high viscosity will cause the pressure pipe to be blocked and the accurate pressure value cannot be measured. Or the pressure tube may leak due to long-term use, resulting in measurement inaccuracy. If this happens, the pressure tube should be replaced in time and regular cleaning and maintenance should be done. Capillary tube problems may occur due to inaccurate selection of pressure oil. In low-temperature working conditions, it is necessary to select appropriate pressure oil to avoid the phenomenon of solidification of the pressure oil due to too low temperatures. Similarly, attention should be paid to avoiding vaporization of the pressure oil at high temperatures.

For details, please contact Qi Huang