Classification of pressure sensors

The pressure sensor is the most widely used type of sensor applied in various industrial automation environments, involving water conservancy and hydropower, railway transportation, intelligent construction, production automation, aerospace, military, petrochemical, oil wells, power, ships, machine tools, pipelines and many other industry.

Commonly used pressure sensors include strain gauge pressure sensors, ceramic pressure sensors, diffusion silicon pressure sensors, sapphire pressure sensors, and piezoelectric pressure sensors. Pressure sensors are categorized by purpose, mainly pressure monitoring, pressure measurement and pressure control and conversion into other quantities. Divided into piezoresistive and piezo-electric sensors according to the power supply mode, the former is passively powered and requires external power. The latter is the sensor itself generates the charge, does not require an external power supply, according to different areas of the pressure measurement accuracy is divided into low accuracy and high precision pressure sensor.

The traditional pressure sensor is mainly composed of a mechanical structure type device, and the pressure is indicated by the deformation of the elastic element. However, this structure has a large size and a heavy weight and cannot provide electrical output. With the development of semiconductor technology, semiconductor pressure sensors have also emerged. Its characteristics are small size, light weight, high accuracy and good temperature characteristics. In particular, with the development of MEMS technology, semiconductor sensors have developed toward miniaturization, and they have low power consumption and high reliability.

Semiconductor pressure resistance type: The semiconductor piezoresistive diffusion pressure sensor forms a semiconductor deformation pressure on the surface of a sheet, deforms the sheet by an external force (pressure) to generate a piezoresistive effect, and thereby converts the impedance change into an electric signal.

Capacitance type: An electrostatic capacity type pressure sensor converts a fixed pole of a glass and a movable pole of silicon to form a capacitance, and converts a change in the capacitance generated by the deformation of the movable pole by an external force (pressure) into an electrical signal. (E8Y's operating principle is electrostatic capacity, other models use semiconductors).