Overview of pressure transmitter

1. Product overview

The pressure transmitter is used to measure the level, density and pressure of liquid, gas or steam, and then convert it into a 4-20mA DC signal output as shown in Figure 1. The pressure transmitter can communicate with the HART handheld communicator, through it to set, monitor or form an on-site monitoring system with the host computer.

2. Working principle

The process pressure of the pressure transmitter is transmitted to the center measuring diaphragm of the d chamber through the isolation diaphragm and filling liquid on both sides or one side. The central diaphragm is a tensioned elastic element, which produces corresponding deformation and displacement for the pressure difference between the two sides acting on it. Its displacement is proportional to the differential pressure, and the maximum displacement is about 0.1mm. This displacement is transformed on the capacitor plate A differential capacitor is formed, and the electronic circuit converts the differential capacitor into a two-wire 4-20mA DC signal output.

Three, installation skills

The installation position of the pressure transmitter on the process pipeline is related to the measured medium. The following conditions should be considered during installation:

1. Try to avoid direct contact between the transmitter and the corrosive or overheated measured medium. To

2. To prevent the dregs from depositing in the pressure guiding tube.

3. The pressure guiding tube should be as short as possible.

4. The liquid column pressure in the pressure guiding tubes on both sides should be balanced. To

5. The pressure guiding tube should be installed in a place where the temperature gradient and temperature fluctuation are small. When measuring the liquid flow, the pressure tap should be opened on the side of the process pipeline to avoid the precipitation of dross. At the same time, the transmitter should be installed beside or below the pressure tap so that air bubbles can be discharged into the process pipeline. When measuring gas flow, the pressure tap should be opened on the top or side of the process pipeline. And the transmitter should be installed beside or on the process pipeline so that the accumulated liquid can easily flow into the process pipeline.