If the working of differential pressure transmitter goes out of order, how can we identify and eliminate the fault?
1. The output value of the transmitter does not go up despite the increase of pressure.
First, check whether the pressure interface is leaking gas or blocked. If not, check the wiring and the power supply. If the power supply works normally, pressurize a bit to see whether the output value changes or there are outputs at the zero position. If there is no change, it means that the transmitter goes wrong, which may be caused by the trouble of the instrument or other parts of the whole system.
2. The output signal of the transmitter is unstable.
This may be caused by the problem of pressure source. Considering the pressure source itself is unstable, this is likely resulted by that the weak anti-interference ability of the instrument or the transmitter. Serious vibration of the transmitter itself or the transmitter failure can also lead to this problem.
3. The output value of pressure transmitter does not change, or the value of pressurized transmitter changes suddenly.
If the pressure relief transmitter cannot return to zero position, it is most likely to be the problem of the seal ring of the pressure sensor. Commonly this is caused by the specification of the seal ring. After the sensor is tightened, the seal ring will be compressed into the pressure port of the transmitter and block the sensor. So, when the pressure is applied, the pressure medium cannot enter. But when the pressure is high, the seal ring will suddenly burst out, and the output value of pressure transmitter will change. The best way to eliminate this kind of fault is to remove the transmitter and check whether the zero position is normal. If it is normal, replace the sealing ring and try again.
4. The offset between the transmitter and the pointer pressure gauge is large.
It is normal to have an offset. Just ensure that the offset is in the normal range.
5. The influence on zero position output by installation position of differential pressure transmitter.
Because the measuring range of differential pressure transmitter is very small, the sensor elements themselves in the transmitter will influence the output value. The pressure sensitive parts of the transmitter should be perpendicular to the gravity when installed. After installation, adjust the zero position to the standard value.