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Smart pressure sensor is The Ideal Choice for Pressure Monitoring Applications.
The intelligent pressure sensor converts the measured physical quantity into a corresponding electrical signal and sends it to the signal dispatching circuit.
Smart pressure sensor can better adopt digital compensation and nonlinear correction technology than ordinary pressure sensor. The optional RS485 interface/HART protocol can configure a more intelligent pressure monitoring and control system.
The most common are diffused silicon pressure sensors and capacitive pressure sensors.
- Diffused silicon pressure sensor.
Its working principle is based on piezoresistive effect, using the principle of piezoresistive effect. The pressure of the measured medium acts directly on the diaphragm of the sensor (stainless steel or ceramics). Make the diaphragm produce a micro-displacement proportional to the medium pressure. The resistance value of the sensor is changed, and the change is detected by the electronic circuit. And convert and output a standard measurement signal corresponding to this pressure.
It is characterized by small size, light weight, stable performance, and is 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.
- Capacitive pressure sensor.
It 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 metallized film as an electrode of the capacitor. When the membrane deforms under pressure, the capacitance formed between the membrane and the fixed electrode changes. By measuring the circuit, an electrical signal that has a certain relationship with the voltage can be output.
It has low input energy, high dynamic response, and small natural effects. Good environmental adaptability and other characteristics. Among them, the ceramic capacitive pressure sensor can be widely used in the pressure detection of various media such as water, gas and liquid due to its advantages of corrosion resistance, impact resistance, no hysteresis, and strong media compatibility.
Different types of pressure sensors have different operating principles. Let’s take a brief look below.
How the pressure sensor works:
- Piezoresistive force sensor: 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 strain resistance changes with mechanical deformation when it is adsorbed on the base material. Commonly known as the resistance strain effect.
- Ceramic pressure sensor: Ceramic pressure sensor is based on piezoresistive effect. The pressure acts directly on the front surface of the ceramic diaphragm. Make the diaphragm slightly deformed. 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 produces 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 different pressure ranges, which can be compatible with strain gauge sensors.
- Diffused silicon pressure sensor: The working principle of the diffused silicon pressure sensor is also based on the piezoresistive effect. Using the principle of piezoresistive effect, the pressure of the measured medium acts directly on the diaphragm of the sensor (stainless steel or ceramics). Make the diaphragm produce a micro-displacement proportional to the medium pressure, and change the resistance value of the sensor. The electronic circuit detects this change, and converts and outputs a standard measurement signal corresponding to this pressure.
- Sapphire pressure sensor: Using the working principle of strain resistance, silicon-sapphire is used as the semiconductor sensitive element. With unrivaled metrological properties. Therefore, the semiconductor sensitive element made of silicon-sapphire is not sensitive to temperature changes, and has good working characteristics even under high temperature conditions. Sapphire is extremely resistant to radiation. In addition, the silicon-sapphire semiconductor sensitive element has no p-n drift.
- Piezoelectric pressure sensor: The piezoelectric effect is the main working principle of the piezoelectric sensor. Piezoelectric sensors cannot be used for static measurements. Because the charge after the external force is only preserved when the circuit has infinite input impedance. The actual situation is not like this. So this determines that the piezoelectric sensor can only measure dynamic stress.
