The pressure sensor is the most commonly used sensor in industrial practice. The traditional pressure sensor is mainly based on the mechanical structure type device, and the pressure is indicated by the deformation of the elastic element. However, this structure is large in size and heavy in weight, and cannot provide electrical output, so It is most commonly used in industrial fields.
With the development of semiconductor technology, semiconductor pressure sensors have emerged as the times require, which are characterized by small size, light weight, high accuracy and good temperature characteristics.Especially with the development of MEMS technology, semiconductor sensors are developing towards miniaturization, and their power consumption is low and reliability is high.
There are many types of pressure sensors, which can be divided into different types according to different classification standards. Here are two of the most common pressure sensors:
1. Diffusion silicon pressure sensor
The working principle of the diffused silicon pressure sensor is based on the piezoresistive effect. Using the piezoresistive effect principle, the pressure of the measured medium directly acts on the diaphragm (stainless steel or ceramics) of the sensor, so that the diaphragm produces a micro-displacement proportional to the medium pressure. The resistance value of the sensor is changed, the electronic circuit is used to detect the change, and a standard measurement signal corresponding to the pressure is converted and output.
Diffusion silicon pressure sensor is small in size, light in weight and stable in performance, suitable for making small range transmitters, mainly used in process control systems, pressure calibration instruments, hydraulic systems, biomedical instruments, hydraulic systems and valves, liquid level measurement, refrigeration equipment and HVAC control industries.
2. Capacitive pressure sensor
Capacitive pressure sensor is a pressure sensor that uses capacitive sensitive elements to convert the measured pressure into an electrical output that has a certain relationship with it.It generally uses a circular metal film or a metal-plated film as an electrode of the capacitor. When the film is deformed by pressure, the capacitance formed between the film and the fixed electrode changes, and the output voltage has a certain relationship with the voltage through the measurement circuit. electric signal.
Capacitive pressure sensors have the characteristics of low input energy, high dynamic response, small natural effects, and good environmental adaptability.Among them, the ceramic capacitive pressure sensor can be widely used in the pressure detection of water, gas and liquid due to its advantages of corrosion resistance, impact resistance, no hysteresis, and strong medium compatibility.
Pressure is one of the important parameters in production and life. Pressure sensors are also widely used in various industrial automation environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automation, petrochemicals, oil wells, electricity, ships, machine tools, pipelines and many other industries. .
Post time: Aug-21-2022