Common failure and removal of transmitter.

Common failure and removal of transmitter.

1. Pressure, the output of the transmitter will not change the output of the pressure transmitter, and the output of the pressure transmitter will change suddenly, and the relief transmitter will not return to zero.

This kind of circumstance should check whether the pressure interface is a flat or clogged, check the connection mode and the power, if normal to see whether the sensor zero output, or for simple pressure to see if the output change, change that sensor was not damaged, if no change sensor that has been damaged. Finally, it may be the problem of instrument damage, or other aspects of the whole system.

2. The transmitter output signal is unstable.

Appear this kind of circumstance should consider a. pressure source itself is an unstable b. instrument or pressure sensor anti-interference ability is not strong c. sensor wiring rickety d. vibration sensor itself is very severe e. sensor fault

3. The output of pressure transmitter does not change, and the output of the pressure transmitter suddenly changes, and the pressure transmitter is zero.

Check the sensor ring, generally because seal specifications (too soft or too thick), sensors and tighten, sealing ring is compressed to sensor pressure inside the mouth jam sensors, pressure pressure medium into not to go, but a lot of pressure when suddenly flung wide sealing ring, pressure sensor and change of stress, and pressure to reduce again, seal and return plug pressure, residual pressure release out, so the sensor zero come down again. The reason for this is to remove the sensor to see if the zero is normal, and try again if the seal ring is normally replaced.

4. The transmitter receives no output.

A fault line (both the meter and the sensor should be checked)B. The fault or short circuit of the wire itself. The power supply is not output or the power supply is not matched. D. the instrument is damaged or the meter is not matched.

5. Transmitter error.

Confirm the method of normal error range: the error of the calculated pressure gauge values such as: pressure gauge range of 30 bar, accuracy is 1.5%, the minimum scale is 0.2 bar normal error is: 30 bar * 1.5% (visual error) = 0.55 + 0.2 * 0.2 bar pressure transmitter error value.

In general, some failure analysis and processing of the transmitter during the use of the transmitter mainly consists of the following methods.

A substitution method:

Prepare a normal transmitter to replace the suspect directly.

This can be simple and quick to determine whether the fault of the transmitter itself is the fault of the pipeline or other equipment.

B method:

Separately from the rest parts of the suspected fault and to see whether the fault disappear, if lost, then determine the malfunction, or can be carried out to find the next, such as: smart differential pressure transmitter can't normal Hart, telecommunication, power supply can be disconnected from the instrument noumenon, the method of field plus a power transmitter power to communicate, to see if the cable is about 2 KHZ electromagnetic signal interfere with communication.

C. short circuit detection:

In the case of security, the related part of the loop short directly, such as: small difference transmitter output value, can guide tube disconnected, from an outside pressure valve directly to the differential pressure signal directly led to the differential pressure transmitter, on both sides to observe the transmitter output, to determine the pipeline wall, leakage of connectivity.