Pressure transmitter
  • Pressure transmitter

Pressure transmitter

Pressure transmitters are used to measure the liquid level, density, and pressure of liquids, gases, or vapors, and then convert them into 4-20mA DC signal outputs. The pressure transmitter can communicate with the Hart manual operator to set, monitor, or form an on-site monitoring system with the upper computer.

1、 Product Overview

Pressure transmitters are used to measure the liquid level, density, and pressure of liquids, gases, or vapors, and then convert them into 4-20mA DC signal outputs. The pressure transmitter can communicate with the Hart manual operator to set, monitor, or form an on-site monitoring system with the upper computer.

2、 Working principle

The process pressure of the pressure transmitter is transmitted to the center measurement diaphragm of chamber d through the isolation diaphragm on both sides or one side, filled with liquid. The central diaphragm is a tensioned elastic element that produces corresponding deformation displacement for the pressure difference on both sides acting on it. Its displacement is proportional to the differential pressure, with a large displacement of about 0.1mm. This displacement transformation forms a differential capacitor on the capacitor plate, which is converted into a two wire 4-20mA DC signal output by an electronic circuit.

3、 Installation tips

The installation position of the pressure transmitter on the process pipeline is related to the measured medium. During installation, attention should be paid to the following situations:

1. Try to avoid direct contact between the transmitter and corrosive or overheated test media.

2. To prevent sediment from settling inside the pressure pipe.

3. The pressure pipe should be as short as possible.

4. The liquid column pressure inside the pressure pipes on both sides should be balanced.

5. Pressure pipes should be installed in areas with low temperature gradients and fluctuations. When measuring liquid flow rate, the pressure tap should be opened on the side of the process pipeline to avoid the sedimentation of slag. At the same time, the transmitter should be installed next to or below the pressure tap to allow bubbles to be discharged into the process pipeline. When measuring gas flow, the pressure tap should be located at the top or side of the process pipeline. And the transmitter should be installed next to or above the process pipeline, so that accumulated liquid can easily flow into the process pipeline.