信號不穩的原因有以下幾種
A.壓力源本身是一個不穩定的壓力
B.儀表或壓力傳感器抗干擾能力不強
C.傳感器接線不牢
D.傳感器本身振動很厲害
E. 傳感器故障
解決方法：
1、被測壓力加上去，但壓力變送器輸出信號上不去：
先應檢查壓力變送器的取壓接口是否漏氣或者被堵住，如果確認不是
可檢查壓力變送器的接線方式，如接線無誤
檢查電源，如電源正常
查看壓力傳感器零位是否有輸出，或者進行簡單加壓看輸出是否變化，有變化證明壓力變送器沒有損壞，如果無變化傳感器即已經損壞。
出現這種情況的其他原因還可能是儀表損壞，或者整個系統的其他環節的問題。
2、加壓變送器輸出不變化，再加壓變送器輸出突然變化，泄壓變送器零位回不去。
此現象的原因極有可能是壓力傳感器密封圈引起的，一般是因為密封圈規格原因（太軟或太厚），壓力變送器擰緊時，密封圈被壓縮到傳感器引壓口里面堵塞傳感器，加壓時壓力介質進不去，但是壓力很大時突然沖開密封圈，壓力傳感器受到壓力而變化，而壓力再次降低時，密封圈又回位堵住引壓口，殘存的壓力釋放不出，因此傳感器零位又下不來。
排除此原因的最佳方法是將傳感器卸下，直接察看零位是否正常，如果正常更換密封圈再試。
There are several reasons for this instability.
A. pressure source itself is an unstable pressure.
B. instrument or pressure sensor is not strong enough to resist interference.
C. sensor wiring is not fast enough.
The D. sensor itself is very vibrant.
E. sensor failure
Resolvent:
1. The measured pressure is added, but the output signal of the pressure transmitter is not going up.
Check whether the pressure interface of the pressure transmitter is leak or blocked, if confirmed.
Check the connection mode of the pressure transmitter, such as wiring error.
Check the power supply, such as normal power supply.
Check whether the pressure sensor zero output, or simply pressurize to see if the output changes, changes prove that the pressure transmitter is not damaged, if there is no change in the sensor has been damaged.
Other reasons for this may be instrumentation damage, or other aspects of the system as a whole.
2. The output of pressure transmitter remains unchanged, and then the output of pressure transmitter suddenly changes, so the zero position of pressure relief transmitter can not be returned.
This phenomenon is most likely caused by the pressure sensor sealing ring, usually because of the sealing ring specifications (too soft or too thick), pressure transmitter tightening, the sealing ring is compressed into the sensor inlet plugging sensor, pressure medium can not go in, but the pressure is very high when suddenly burst open the sealing ring, The pressure sensor is changed by pressure, and when the pressure decreases again, the sealing ring returns to plug the suction port, and the residual pressure can not be released, so the sensor zero position can not come down.
The best way to eliminate this is to remove the sensor and check the zero position directly to see if it is normal. If the seal ring is replaced properly, try again.
