第三种是变送器输出信号不稳。这种故障有可能是压力源的问题。压力源本身是一个不稳定的压力，很有可能是仪表或压力传感器抗干扰能力不强、传感器本身振动很厉害和传感器故障；第四种是变送器与指针式压力表对照偏差大。出现偏差是正常的现象，确认正常的偏差范围即可；

    ***一种易出现的故障是微差压变送器安装位置对零位输出的影响。微差压变送器由于其测量范围很小，变送器中传感元件会影响到微差压变送器的输出。安装时应使变送器的压力敏感件轴向垂直于重力方向，安装固定后调整变送器零位到标准值。

The third is that the output signal of the transmitter is unstable. This kind of failure may be the problem of pressure source. The pressure source itself is an unstable pressure, which is likely to be due to the weak anti-interference ability of the instrument or pressure sensor, severe vibration of the sensor itself and sensor failure; The fourth is that the deviation between the transmitter and the pointer pressure gauge is large. Deviation is a normal phenomenon, and it is OK to confirm the normal deviation range;

The last easy fault is the influence of the installation position of the micro differential pressure transmitter on the zero output. Because the measuring range of micro differential pressure transmitter is very small, the sensor elements in the transmitter will affect the output of micro differential pressure transmitter. During installation, make the axial direction of the pressure sensitive part of the transmitter vertical to the direction of gravity, and adjust the zero position of the transmitter to the standard value after installation and fixation.