The sensor is a detecting device that can sense the measured information and can transform the detected information into an electrical signal or other required form of information output according to a certain law to meet the information transmission, processing, storage, Requirements for display, recording and control. It is the first step in achieving automatic detection and automatic control. There are many ways to classify sensors, which are distinguished according to different principles:
1. According to the measured physical quantity: such as: force, pressure, displacement, temperature, angle sensor, etc.;
2, according to the working principle of the sensor: such as: strain sensor, piezoelectric sensor, piezoresistive sensor, inductive sensor, capacitive sensor, photoelectric sensor, etc.;
3. According to the way the sensor converts energy:
(1) Energy conversion type: such as: piezoelectric type, thermocouple, photoelectric sensor, etc.;
(2) Energy control type: such as: resistive, inductive, Hall-type sensors and thermistors, photoresistors, humidity-sensitive resistors, etc.;
4. According to the working mechanism of the sensor:
(1) Structure type: such as: inductive, capacitive sensor, etc.;
(2) Physical properties: such as piezoelectric, photoelectric, various semiconductor sensors, etc.;
5. According to the form of the sensor output signal:
(1) Analog: The sensor output is an analog voltage;
(2) Digital: The sensor output is digital, such as: encoder sensor.
6, according to the principle of energy conversion can be divided into:
(1) Active sensors: Active sensors convert non-electricity into electrical energy, such as electromotive force, charge sensors, etc.;
(2) Passive sensors: Passive program sensors do not have energy conversion, but only convert the measured non-electricity into electrical parameters, such as resistive, inductive and capacitive luminescence sensors.