Five types of pressure sensors

What is a pressure sensor?

The pressure sensor converts the received pressure signals of gas, liquid, etc. into a standard current signal (4~20mADC) and supplies it to secondary instruments such as indicator alarms, recorders, and regulators for measurement. Components used for indication and process regulation, let me show you how to do it next

Piezoelectric pressure sensor

Piezoelectric pressure sensors are mainly based on the piezoelectric effect. They use mechanical devices such as electrical components to convert the pressure to be measured into electrical energy, and then perform related measurements. Precision instruments, such as many pressure transmitters and pressure sensors, etc., can be used for static measurements. The reason is that the charge after being acted upon by external forces can only remain in its original state when the circuit has infinite input impedance, but this is not the case in reality, so piezoelectric sensors cannot be used for static measurements. Sensors can only be used for dynamic measurements.

Piezoresistive pressure sensor

Piezoresistive pressure sensors are mainly based on the piezoresistive effect. The piezoresistive effect is used to describe the change in resistance of a material under mechanical stress. Unlike the piezoelectric effect mentioned above, the piezoresistive effect only produces impedance changes and does not generate charge. Most metals and semiconductor materials have been found to have piezoresistive effects. Among them, the piezoresistive effect in semiconductor materials is much greater than that in metals.

Capacitive pressure sensor

Capacitive pressure sensor is a pressure sensor that uses capacitance as a sensitive element and converts the measured pressure into a change in capacitance value. This type of pressure sensor generally uses a circular metal film or a metal-plated film as the 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 is proportional to the voltage through the measuring circuit. An electrical signal with a certain relationship.

Electromagnetic pressure sensor

A general term for various sensors that use electromagnetic principles, including inductive pressure sensors, Hall pressure sensors, eddy current pressure sensors, etc. The working principle of inductive pressure sensor is that due to the difference in magnetic materials and magnetic permeability, when pressure acts on the diaphragm, the size of the air gap changes, and the change of the air gap affects the change of the coil inductance. The processing circuit can convert this change of inductance into a corresponding signal output, thereby achieving the purpose of measuring pressure.

Vibrating Wire Pressure Sensor

Vibrating Wire Pressure Sensor is a frequency-sensitive sensor. This frequency measurement has extremely high accuracy because time and frequency are physical parameters that can be accurately measured. In the process of frequency signal transmission, the influence of cable resistance, inductance, capacitance and other factors can be ignored.