English name: transducer / sensor Sensor is a physical device or biological organ， can detect， feel the outside world signals， the physical conditions (such as light， heat， humidity) or the chemical composition (such as smoke)， and finding out information to other devices or The definition of sensor National Standard GB7665-87 under the definition of the sensor are: "can feel the provisions must be measured and in accordance with the law can be used to convert the signal device or devices， usually from sensitive components and conversion " Sensor is a detection device， can be felt by measuring the information， and can feel Detected information， according to the law of transformation must be a signal or other form of information required for the output to meet the needs of information transmission， processing， storage， display， recording and control is the automatic detection and automatic implementation of the primary Sensor classification Different points of view can be used to classify the sensor: the principle of their conversion (sensor basic physical or chemical effect); their uses; their output signal type and the production of their materials and According to the sensor working principle， can be divided into physical sensors and chemical sensors two broad categories: Sensor working principle of the classification of the physical sensor applications are physical effects， such as the piezoelectric effect， magnetostriction phenomenon， ionization， polarization， thermoelectric， photovoltaic， magnetic effects， such as Measured the volume of small changes in signal will be converted to electrical Chemical sensors， including those by chemical adsorption， electrochemical reaction， such as the situation for the causal relationship between sensors， the measured signal small changes in volume will also be converted into electrical Some sensors can not divided into the physical category， it should not be divided into chemical Most of the sensor is based on basic physical principles for the Chemical sensor technology more questions， such as reliability issues， the possibility of mass production， prices ， and have solved these problems， the application of chemical sensors will have 。 Common sensor applications and operating principle are presented in Table In accordance with its purposes， the sensor can be classified as: Stress sensitivity and the force sensor position sensor � Level sensor � energy sensor Speed Sensor � thermistor sensor Acceleration sensor �-ray radiation sensor vibration sensor humidity sensor Magnetic Sensor Gas Sensor Vacuum sensors biosensors， � � � Its output signal as the standard sensors can be divided into: Analog sensors - will be measuring the volume of non-electrical converted into analog � � sensor - will be measured non-electrical quantity into a digital output signal (both direct and indirect conversion) � � Ying digital sensor - will be measuring the amount of signal into frequency signals， or short-cycle signal output (including direct or indirect conversion) � � 。 Switch sensor - When a measurement signal to achieve a specific threshold， the sensor output corresponding to a specified low or high � � At the role of external factors， all materials will be made accordingly， with a characteristic Them the role of those outside the most sensitive material， that is， those with functional properties of the material， was used to produce a sensor sensitive Materials from the application point of view of the sensor can be divided into the following categories: � (1) in accordance with the category of Materials � according to the physical properties of materials at (2) � � conductor insulator semiconductor � � magnetic � (3) The crystal structure of sub-Materials � Single crystal polycrystalline � � � Amorphous Materials ：� With the use of new materials is closely related to the development of the sensor can be summed up in the following three directions: � (1) at a known material to explore new phenomena， effects and response， and then enable them to be at sensor technology actually � � (2) to explore new materials， application of those known phenomenon， effects and response to improve the sensor � � (3) at the basic research on new materials to explore new phenomena and new effects and reactions， and in sensor technology to be the specific � � Modern sensor manufacturing progress depends on sensor technology for new materials and sensitive components of the development of The basic trend of the sensor development are dielectric materials and semiconductor applications， as well as closely Table 2 can be used to give a number of sensor technology， be able to convert energy forms of � � ： In accordance with its manufacturing process， the sensor can be divided into: Integrated thin-film sensor sensors � � � ceramic thick-film sensor sensor Integrated sensors are produced using standard silicon-based technology of semiconductor integrated circuits Will also be used for the initial treatment is usually measured part of the signal circuit is also integrated in the same � � Thin-film sensor is deposited on dielectric substrates through (substrate) on the corresponding sensitive material film The use of hybrid technology， the same part of the circuit can be manufactured on this � � Thick-film sensor is the use of the corresponding material slurry， coating on the ceramic substrate made of， the substrate is usually made of Al2O3， and then heat-treated， so that thick-film Ceramic sensors using standard ceramic technology， or some variant of process (sol - gel， ) � � Completed the appropriate preparatory actions， have been forming components at high temperature in Thick film and ceramic sensors that between two kinds of processes have many common characteristics， in some respects， you can think of ceramic art thick film technology is a � � Each technology has its own strengths and Because of the research， development and production of a lower capital investment requirements， as well as the high stability of the sensor parameters and other reasons， the use of ceramics and thick film sensors more
