The pressure transmitter's precautions

Precautions for the pressure transmitters wiring diagram in daily use 

Do not apply a voltage higher than 36V to the transmitter, which will cause damage to the transmitter; 

Do not touch the diaphragm with hard objects, which will cause the isolation membrane The film is damaged;

The measured medium is not allowed to freeze, otherwise it will damage the sensor element isolation diaphragm and cause damage to the transmitter. If necessary, the transmitter needs to be temperature protected to prevent freezing

 When measuring steam or For other high-temperature media, the temperature should not exceed the limit temperature when the transmitter is used, and a heat sink must be used when the temperature is higher than the limit temperature used by the transmitter; 

When measuring steam or other high-temperature, the transmitter and the pipeline are connected together, and the pressure on the pipeline is used to transmit to the transformer. When the measured medium is water vapor, Inject an appropriate amount of water to prevent the superheated steam from directly contacting the transmitter and damaging the sensor;

 During the pressure transmission process, the following points should be noted:

Do not leak air at the connection between the transmitter and the heat pipe;

Before starting to use, if the valve is closed, the valve should be opened very carefully and slowly during use, so as not to directly impact the sensor diaphragm by the measured medium, thereby damaging the sensor diaphragm;

The pipeline must be kept unblocked, and the sediment in the pipeline will pop up and damage the sensor diaphragm; fault diagnosis and analysis of the pressure transmitter wiring diagram in the application:

1. Investigation method: review the sparking, smoke, peculiar smell, power supply changes, lightning strikes, moisture, misoperation, mismaintenance.

2. Intuitive method: Observe the external damage of the circuit, the leakage of the pressure guiding tube, the overheating of the circuit, and the Electric switch status, etc.

Detection method of pressure transmitter yokogawa

1. Open circuit detection: separate the suspected faulty part from the other parts to check whether the fault disappears. If it disappears, determine the fault location, otherwise you can go to the next step to find it, such as: the wiring diagram of the intelligent intelligent differential pressure transmitter cannot For normal Hart remote communication, the power can be disconnected from the meter body, and the transmitter can be energized for communication by adding an additional power source on site to see if the cable is superimposed with an electromagnetic signal of about 2kHz to interfere with the communication.

2. Short-circuit detection: Under the condition of ensuring safety, directly short-circuit the relevant part of the circuit. Directly lead to both sides of the wiring diagram of the smart differential pressure transmitter and observe the transmitter output to determine the plugging and leaking connectivity of the pressure guiding pipeline.

3. Replacement detection: replace the suspected faulty part and judge the faulty part. For example, if you suspect that the transmitter circuit board is malfunctioning, you can temporarily replace one to determine the cause.

4. Subsection detection: Divide the measurement loop into several parts, such as: power supply, signal output, signal transmission, signal detection, and check by subsection, from simple to complex, from the table to the inside, narrow the scope, and find the fault Location.