What are the common faults of pressure transmitter

1. The working pressure label fluctuates greatly

When checking the load, refer to the main parameters of other processing technologies to see what changes are made. If the main parameters of other processing technologies, such as temperature, total flow and liquid level, will fluctuate, if the working pressure changes due to load change, the pressure transmitter should have no problem; if there is no change in other processing technology standards, Only the working pressure is marked in ups and downs, it depends on the working pressure display information with no manipulation. It is usually used to adjust the valve. Check whether the output of the positioner on the regulating valve is moving at a constant speed, not at a uniform speed. It is necessary to solve the problem of gate valve. If it operates at a constant speed, you will be out of the transmitter. On the spot, turn off the pressure of the transmitter, turn on the blowdown, and check whether the transmitter displays information 0. If the display information 0 point, the accurate measurement of the transmitter is not difficult, but also check the cable from the transmitter to the DCS server cabinet, and check whether the shielding of the branch cable and the main cable is intact, which is generally caused by the disconnection of the shielding cable or the virtual connection at the cable connection and the loose caused by the air oxidation of the exposed cable core. Shielding is not very good, its natural environment has a lot of interference signals, such ups and downs are serious. In view of the accurate measurement of the working pressure of steam substances, if the indication is suddenly high or low, it is necessary to check the condensate volume in the pressure pipe. If there is electric heat tracing, check whether the temperature and installation distance of the heat tracing pipe are harmful to the condensate in the pressure pipe. If the temperature is too high and the installation distance between the heat tracing pipeline and the pressure pipe is too close, the condensate vaporization will be caused and the accurate measurement will be prohibited and fluctuated. Another question is whether the length of the impulse pipe can ensure sufficient cooling and reduce the harm of processing material pulsation to accurate measurement.

2. No information is displayed

The basis is to be able to distinguish the cable loose and short circuit of the instrument panel. For different DCS automatic control systems, when the cable is short circuited on the spot, the marking of the relative point of the processing technology will have different main expression methods. Can distinguish according to different reminders. In that case, the cables from the terminal cabinet to the junction box and the transmitter should be checked point by point.

3. The label does not change with the processing technology

This also needs to check the pressure transmitter to clear itself to many times on the pressure valve that the pipeline where there is blocking. For example, in the pipeline in the whole process of transportation of the granular material system software, there is always a blind area in the impulse pipe for accurate measurement of working pressure, which will lead to the deposition of granular materials in the pressure pipe. If the time is long, the transmission of working pressure will not be the same, and the label will not change greatly.

There is a big error in the marking

Check whether the zero point of the transmitter is appropriate. If the zero point drift of the transmitter, it is necessary to zero the transmitter again; and carry out pressure calibration on the transmitter to check whether the output of the transmitter is intact.