Brief introduction of pressure transmitter

Brief introduction of pressure transmitter

The pressure transmitter is an instrument that transmits the pressure value to the control room or display meter based on the pressure measurement.A sensor commonly used in industrial practice, which is widely used in various industrial automatic control environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automatic control, aerospace, military industry, petrochemical, oil wells, electric power, ships, machine tools, pipelines, etc. industry.The following is a brief introduction to the principles and applications of some commonly used pressure transmitters. The pressure transmitter is used to measure the liquid level, density and pressure of liquid, gas or steam, and then convert the pressure signal into a 4 ~ 20mA DC signal output.

Pressure transmitters mainly include capacitive pressure transmitters, diffused silicon pressure transmitters, ceramic pressure transmitters, strain gauge pressure transmitters, etc.Pressure transmitters can be divided into general pressure transmitters (0.001MPa ~ 35MPa) and differential pressure transmitters (0 ~ 1.5kPa) and negative pressure transmitters according to the pressure measurement range.

The main function of the pressure transmitter is to transmit the pressure signal to the electronic device, and then display the pressure on the computer. The magnitude of the current has a linear relationship, generally a proportional relationship.Therefore, the voltage or current output by the transmitter increases with the increase of pressure, and thus a relationship between pressure and voltage or current is obtained. The two pressures of the measured medium of the pressure transmitter are passed into the high and low pressure chambers. , The pressure of the low-pressure chamber adopts atmospheric pressure or vacuum, which acts on the isolation diaphragm on both sides of the sensitive element, and is transmitted to both sides of the measuring diaphragm through the isolation diaphragm and the filling liquid in the element.

The pressure transmitter is composed of a measuring diaphragm and electrodes on both sides of the insulating sheet to form a capacitor.When the pressure on both sides is inconsistent, the measuring diaphragm is displaced, and the displacement is proportional to the pressure difference, so the capacitance on both sides is not equal, through the oscillation and demodulation link.