sensor
Sensor (English name: transducer/sensor) is a kind of detection device, which can sense the measured information and transform the sensed information into electrical signals or other required forms of information output according to certain rules to meet the requirements of information transmission, processing, storage, display, recording and control. The sensor is generally composed of four parts: sensing element, conversion element, conversion circuit and auxiliary power supply. The sensing element directly feels the measured, and outputs the physical quantity signal that has a definite relationship with the measured; The conversion element converts the physical quantity signal output by the sensing element into an electrical signal; The conversion circuit is responsible for amplifying and modulating the electrical signal output by the conversion element; In general, conversion components and circuits also need auxiliary power supply. Main functions of sensors: compared with the five human sensory organs, photosensitive sensors - vision, acoustic sensors - hearing, gas sensors - smell, chemical sensors - taste, pressure, temperature, fluid sensors - touch. Common sensor classifications include: resistance sensor is a device that converts measured physical quantities such as displacement, deformation, force, acceleration, humidity, temperature, etc. into resistance value. It mainly includes resistance strain sensor, piezoresistance sensor, thermal resistance sensor, thermal sensor, gas sensor and humidity sensor. The thermal resistance sensor mainly uses the characteristic that the resistance value changes with temperature to measure temperature and temperature related parameters. This kind of sensor is suitable for the occasions where the temperature detection accuracy is required to be high. The widely used thermal resistance materials are platinum, copper, nickel, etc. They have the characteristics of large resistance temperature coefficient, good linearity, stable performance, wide temperature range of use, easy processing, etc. It is used to measure the temperature within the range of - 200 ℃~+500 ℃. Hall sensor is a kind of magnetic field sensor based on Hall effect, which is widely used in industrial automation technology, detection technology and information processing. Hall effect is a basic method to study the properties of semiconductor materials. The Hall coefficient measured by Hall effect experiment can judge the important parameters of semiconductor materials, such as the conductive type, carrier concentration and carrier mobility. Pressure sensor is the most commonly used sensor in industrial practice. It is widely used in various industrial automatic control environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automation, aerospace, military, petrochemical, oil wells, power, ships, machine tools, pipelines and many other industries.