Do you know the pressure sensor and pressure type?

- Nov 06, 2020-

Working principle

1. Piezoresistive pressure sensor

The resistance strain gauge is one of the main components of piezoresistive strain sensor. The working principle of the metal resistance strain gauge is the phenomenon that the resistance value of the strain resistance changes with the mechanical deformation, which is commonly known as the resistance strain effect.

2. Ceramic pressure sensor

The ceramic pressure sensor is based on the piezoresistive effect. The pressure directly acts on the front surface of the ceramic diaphragm, causing a slight deformation of the diaphragm. The thick film resistor is printed on the back of the ceramic diaphragm and connected to a Wheatstone bridge. The piezoresistive effect makes the bridge generate a highly linear voltage signal proportional to the pressure and also proportional to the excitation voltage. The standard signal is calibrated to 2.0/3.0/3.3mV/V according to the pressure range. Compatible with strain gauge sensors.

3. Diffusion silicon pressure sensor

The working principle of the diffused silicon pressure sensor is also based on the piezoresistive effect. Using the principle of the piezoresistive effect, the pressure of the measured medium directly acts on the diaphragm (stainless steel or ceramic) of the sensor, causing the diaphragm to produce a micro displacement proportional to the pressure of the medium. The resistance value of the sensor is changed, the electronic circuit is used to detect this change, and a standard measurement signal corresponding to this pressure is converted and output.

4. Sapphire pressure sensor:

Utilizing the working principle of strain resistance, using silicon-sapphire as the semiconductor sensitive element, it has unparalleled measurement characteristics. Therefore, the semiconductor sensor made of silicon-sapphire is not sensitive to temperature changes and has good working characteristics even under high-temperature conditions; sapphire has strong radiation resistance; in addition, silicon-sapphire semiconductor sensor has no PN drift.

5. Piezoelectric pressure sensor:

The piezoelectric effect is the main working principle of the piezoelectric sensor. The piezoelectric sensor cannot be used for static measurement, because the electric charge after the action of external force can only be saved when the circuit has an infinite input impedance. The actual situation is not like this, so this determines that the piezoelectric sensor can only measure dynamic stress.

Type of pressure

Absolute pressure: The pressure value measured when the reference pressure is vacuum is absolute pressure, usually referred to as absolute pressure.

Gauge pressure: When the reference pressure is the local atmospheric pressure, the measured pressure is the gauge pressure. Gauge pressure is referred to as pressure when it is positive, and negative pressure or vacuum when it is negative. The greater the absolute value of the negative pressure, that is, the smaller the absolute pressure, the greater the vacuum.

Differential pressure: When the measured pressure is felt at both ends of the sensor or transmitter, the difference between the pressures at both ends is called differential pressure.

pressure transmitter