The sensor is a detection device, can feel the measured information, and can feel the information, according to certain laws, transformed into electrical signals or other required forms of information output to meet the information transmission, processing, storage, display, recording and control requirements.
According to the Chinese national standard GB7665-87 on the definition of the sensor, the sensor is able to feel the measured parts and in accordance with certain laws (mathematical function law) into a usable signal device or device, usually by the sensitive components and conversion components. Sensor is able to feel the prescribed measurement and according to certain laws into a usable output signal device or device, the output signal is generally power.
Sensor, can feel the prescribed measurement and in accordance with certain laws into a usable output signal device or device. Usually have a sensitive element and conversion element, sensitive element is the sensor can be directly (or response) is measured in the part. Conversion element refers to the sensor can be more sensitive elements feel (or response) of the measurement is converted to transmission and (or) measurement of the electrical signal part.
The characteristics of the sensor include: miniaturization, digitalization, intelligence, multifunctionality, systematization, networking. It is the realization of automatic detection and automatic control of the primary link. It is usually divided into ten categories according to its basic sensing function such as heat-sensitive element, light-sensitive element, gas-sensitive element, force-sensitive element, magnetic-sensitive element, moisture-sensitive element, acoustic-sensitive element, radiation-sensitive element, color-sensitive element and taste-sensitive element.
Expanded information;
Sensors can be divided into the differences in the sensitive materials used: SnO2 class, ZnO class, Fe2O3 class. Because of the many types of doping, this classification is not accurate; when the heater and semiconductor materials for the isolation of the state, the structure of this class of sensors is the parthermal gas sensor.
By the difference in the internal structure of the sensor can be divided into the side of the heat (ceramic tube type), direct heat (ball bead), plane type (chip structure), the measured gas in the semiconductor surface and the chemical reaction with the oxygen usually requires a certain temperature, to obtain the required temperature must be through the heater to the sensor electrically heated.
When the heater is in direct contact with the semiconductor material, this type of structure of the sensor is a direct thermal gas sensor; planar belongs to the side of the thermal type of one, because of its chip structure is also known as the chip element, printing technology in this type of sensor on the application of more to improve the mechanization of the sensor.
Reference? Baidu Encyclopedia - sensors