The true meaning of pressure sensor

There are many sensors, so do you know pressure sensors? There are many types of sensors in different categories. Let’s talk about pressure sensors today. See if there are any inconsistencies with what you know yourself. 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.

Pressure sensors usually consist of pressure sensitive components and signal processing units. According to different test pressure types, pressure sensors can be divided into gauge pressure sensors, differential pressure sensors and absolute pressure sensors. Pressure sensors are the most commonly used sensors in industrial practice. They are widely used in various industrial automatic control environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automation, aerospace, military industry, petrochemicals, oil wells, electric power, ships, and machine tools. , pipelines and many other industries. Here is a brief introduction to some commonly used sensor principles and applications. There are also medical pressure sensors.

working principle:

1. Piezoresistive pressure sensor

Resistive strain gauge is one of the main components of piezoresistive strain sensor. The working principle of metal resistance strain gauges is that the strain resistance adsorbed on the base material changes resistance due to mechanical deformation, 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 the diaphragm to undergo slight deformation. The thick film resistor is printed on the back of the ceramic diaphragm and connected to form a Wheatstone bridge. Due to the piezoresistor The piezoresistive effect causes the bridge to generate 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 can be combined with Compatible with strain gauge sensors.

3. Diffused 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 of the sensor (stainless steel or ceramic), causing the diaphragm to produce a micro-displacement that is proportional to the medium pressure. The resistance value of the sensor is changed, the electronic circuit is used to detect this change, and a standard measurement signal corresponding to the pressure is converted and output.

4. Sapphire pressure sensor

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

5. Piezoelectric pressure sensor

The piezoelectric effect is the main working principle of piezoelectric sensors. Piezoelectric sensors cannot be used for static measurements because the charge after external force is only preserved when the loop has infinite input impedance. The actual situation is not like this, so this determines that the piezoelectric sensor can only measure dynamic stress. The above is the relevant technical knowledge of pressure sensors. I hope it can help you.