Pressure sensors are indispensable components in industrial automation and intelligent devices. They can accurately measure and monitor various pressure changes. Pressure sensors can be divided into many types according to their working principles and materials. The following are several common pressure sensors and their working principles:
● Piezoresistive pressure sensor
The main component of the piezoresistive pressure sensor is the resistance strain gauge. This sensor uses a metal resistance strain gauge adsorbed on the base material. When subjected to mechanical deformation, the resistance value will change. This phenomenon is called the resistance strain effect.
● Ceramic pressure sensor
The ceramic pressure sensor is based on the piezoresistive effect. The pressure acts directly on the front surface of the ceramic diaphragm, causing the diaphragm to deform slightly. Thick film resistors are printed on the back of the ceramic diaphragm and connected to form a Wheatstone bridge. Due to the piezoresistive effect of the varistor, the bridge generates a highly linear voltage signal that is proportional to the pressure and proportional to the excitation voltage. The standard signal is calibrated to 2.0/3.0/3.3mV/V, etc. according to the different pressure ranges, and is compatible with strain sensors.
● Diffused silicon pressure sensor
The working principle of the diffused silicon pressure sensor is also based on the piezoresistive effect. The pressure of the measured medium directly acts on the diaphragm of the sensor (stainless steel or ceramic), causing the diaphragm to produce a micro-displacement proportional to the medium pressure, thereby changing the resistance value of the sensor. This change is detected by the electronic circuit and converted to output a standard measurement signal corresponding to this pressure.
These pressure sensors play an important role in various industrial applications, ensuring the normal operation and safety monitoring of equipment. Understanding their working principles and classification will help to better select and apply these sensors.
