During the field use of differential pressure transmitters, how do we judge whether their working status is normal? Since most of the faults of differential pressure transmitters are zero drift and blockage of pressure pipes, the scale is rarely calibrated point by point on site, but the zero point and change trend of the differential pressure transmitter are checked. The specific operation steps are as follows:
Zero point check: Close the positive and negative stop valves and open the balance valve. At this time, the output current of the differential pressure transmitter should be 4mA.
Check the changing trend: After the zero-point check of the differential pressure transmitter, each valve returns to its original state, and the drain valve of the negative pressure chamber is opened. The output of the differential pressure transmitter should be maximum. If the positive pressure drain valve is opened, the output is minimum. When the drain valve is opened, little or no measured medium is discharged, indicating that the pressure pipe is blocked. The pressure pipe of the differential pressure transmitter needs to be unblocked.
When the differential pressure transmitter fails to work properly due to various reasons, our staff will make timely judgments on site, find out the cause of the failure, and promptly investigate and solve it, so as to minimize the loss of the entire production process.