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Definition, classification, function, principle and characteristics of pressure transmitter

Definition of pressure transmitter

In general, a pressure transmitter consists of three parts: a load cell sensor (also called a pressure sensor), a measurement circuit, and a process connection.
It can convert the physical pressure parameters, such as gas and liquid, sensed by the load cell sensor into standard electrical signals (such as 4-20mADC, etc.) to provide secondary instruments such as alarm indicators, recorders, and regulators for measurement and indication. And process adjustments.

Classification of pressure transmitters

Pressure transmitters can be divided into general pressure transmitters (0.001MPa ~ 35MPa) and differential pressure transmitters (0 ~ 1.5kPa) according to the measurement range, three kinds of negative pressure transmitters; from the perspective of accuracy, because The accuracy of our national standard is 0.5%. So in recent years it can be divided into high precision pressure transmitter (0.1% or 0.2% or 0.075%) and general pressure transmitter (0.5%)

The role of the pressure transmitter

The pressure transmitter transmits the pressure signal to the electronic device, which in turn displays the pressure on the computer.

The principle of the pressure transmitter:

The mechanical signal of the pressure of water pressure is converted into a current (4-20 mA). The pressure of the electronic signal is linear with the magnitude of the voltage or current, which is generally proportional. Therefore, the voltage or current output by the transmitter increases with pressure. The increase thus yields a relationship between pressure and voltage or current.

The pressure of the measured medium of the pressure transmitter enters the high and low pressure chambers, and the pressure of the low pressure chamber is atmospheric pressure or vacuum, acting on the isolating diaphragm on both sides of the δ element (ie, the sensitive component), through the spacer and The filling liquid in the element is sent to both sides of the measuring diaphragm. The pressure transmitter consists of a capacitor formed by the measuring diaphragm and the electrodes on both sides of the insulating sheet. When the pressures on both sides are inconsistent, the measurement diaphragm is displaced, and the displacement is proportional to the pressure difference, so the capacitance on both sides is not equal, and is converted into a signal proportional to the pressure through the oscillation and demodulation links.

Pressure transmitter features

1) The use of a wide range of measured media, can measure oil, water and paste compatible with 316 stainless steel and 304 stainless steel, with a certain degree of anti-corrosion capabilities.
2) High accuracy, high stability, selection of imported original sensors, good linearity, high temperature stability.
3) small size, light weight, installation, debugging, easy to use
4) Stainless steel fully enclosed housing, waterproof.
5) The pressure sensor directly senses the measured liquid level pressure, and is not affected by the foaming and deposition of the medium.

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