[Popular Science] Detailed current sensor of the type (a)
sensor is an essential product of the information age, almost everywhere. It is the key to human access to information from the outside world. Now people rely on their sense organs, in the study of natural phenomena and laws as well as production activities in their function is far enough.
Now all has been miniaturized sensors, digital, intelligent, multi-functional, systematic, network. As the main direction of development, it is important to realize automatic link detection and automatic control. The existence and development of the sensor, so that objects have touch, taste and smell and other senses, so that the object slowly become alive again. The basic functionality typically divided into thermal sensing element, the photosensitive member, gas sensors, force sensitive element, the magnetic sensing element, a humidity sensor, an acoustic sensor, a radiation-sensitive element, the color and flavor-sensitive element sensitive elements and other ten categories .
Miniaturization is established (MEMS) technology based on microelectromechanical systems, has been successfully applied on a silicon pressure sensor made of silicon device. The following describes the classification of several sensors.
1, the sensor is a resistive resistance to be measured, such as displacement, deformation, force, acceleration, humidity, temperature and other physical quantities converted into a resistance value of formula such a device. There are resistive strain gauge, piezoresistive, thermal resistance, thermal, gas, humidity and other resistive sensor element.
2, it is a weighing load cell capable of electromechanical conversion gravity into an electric signal, is a key component of the electronic instrument. There are a variety of sensors can be realized electromechanical conversion, common resistive strain gauge, the electromagnetic force and capacitive like. An electromagnetic force balance type is mainly used in electronic, capacitive part for electronic crane, while the majority of products used in weighing or resistance strain gauge load cell. Resistance strain gauge load cell structure is relatively simple, high accuracy, wide application, and can be used under relatively poor conditions. So that the resistance strain gauge load cell has been widely used in the instrument.
3, piezoresistive sensors are piezoresistive device according to piezoresistive effect of a semiconductor material on a substrate of a semiconductor material made of diffused resistor. Which substrate may be directly measured as the sensing element, the diffusion resistance in the substrate to be electrically connected to form a bridge. When the substrate is deformed by external force, the resistance values vary, the bridge will have a corresponding unbalanced output. Piezoresistive sensor is used as a substrate piezoresistive sensors (or diaphragm) and the main material for silicon germanium film, silicon sensitive material is made more and more people's attention, especially in the measured pressure solid state piezoresistive sensor applications and speed the most common.
