Pressure sensor is the most commonly used sensor in industrial practice. It 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 and many other industries, the following is a brief introduction to the principles and applications of some commonly used sensors.
A pressure sensor is a device or device that can sense pressure signals and convert the pressure signals into usable output electrical signals according to certain rules. A pressure sensor usually consists of a pressure sensitive element and a signal processing unit.
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 adsorbed on the base material changes with mechanical deformation, commonly known as the resistance strain effect.
The ceramic pressure sensor is based on the piezoresistive effect. The pressure acts directly 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. Due to the piezoresistor The piezoresistive effect makes the bridge generate a highly linear voltage signal proportional to the pressure and proportional to the excitation voltage. The standard signal is calibrated as 2.0/3.0/3.3mV/V according to the pressure range, which can be compared with Compatible with strain gauge sensors.
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 of the sensor (stainless steel or ceramics), so that the diaphragm produces a micro-displacement proportional to the pressure of the medium. Make the resistance value of the sensor change, use the electronic circuit to detect this change, and convert and output a standard measurement signal corresponding to this pressure.
The piezoelectric effect is the main working principle of the piezoelectric sensor. The piezoelectric sensor cannot be used for static measurement, because the charge after the external force is only preserved when the circuit has an infinite input impedance. The actual situation is not like this, so this determines that the piezoelectric pressure sensor can only measure the dynamic stress.