Some detail common sensor characteristics

Sensors are a must-have in the information age and can be found almost everywhere. It is the key to getting information from the outside world. Now people rely solely on their own sense organs, in the study of natural phenomena and laws and production activities in their function is far from enough. To accommodate this, sensors are needed. Therefore, it can be said that the sensor is the extension of human facial features, also known as electrical features.

1, resistance type

 Resistive sensor is a device that converts measured physical quantities such as displacement, deformation, force, acceleration, humidity and temperature into resistance values. The main resistance strain type, piezoresistive type, thermal resistance, heat sensitive, gas sensitive, humidity sensitive resistance sensor parts.

2, weighing

 As a key component of electronic weighing apparatus, the weight sensor is a kind of mechanical and electrical conversion device which can convert gravity into electrical signal. There are many kinds of sensors that can realize the conversion of force and electricity, the common ones are resistance strain type, electromagnetic force type and capacitance type. Electromagnetic force type is mainly used in electronic balance, capacitive type is used in part of the electronic crane scale, and the vast majority of weighing products used or resistance strain type weighing sensor. The resistance strain type weighing sensor has the advantages of simple structure, high accuracy, wide application, and can be used in relatively poor environment. So the resistance strain type weighing sensor has been widely used in weighing apparatus.

3, piezoresistive type

Piezoresistive sensor is a device made of diffusion resistance on the substrate of semiconductor material according to the piezoresistive effect of semiconductor material. The substrate can be directly used as a measurement sensing element, and the diffusive resistance is connected into a bridge form in the substrate. When the substrate is deformed by external forces, the resistance values will change, and the bridge will produce the corresponding unbalanced output.

The substrate (or diaphragm) material used as piezoresistive sensor is mainly silicon chip and germanium chip, silicon chip is made of sensitive material and silicon piezoresistive sensor is more and more attention, especially to measure the pressure and speed of the solid piezoresistive sensor application is the most common.

4, laser

A sensor that uses laser technology to make measurements. It consists of a laser, a laser detector and a measuring circuit. Laser sensor is a new type of measuring instrument, its advantages are to achieve distance measurement without contact, fast speed, high precision, large range, strong resistance to light and electrical interference.

When the laser sensor works, the laser emitting diode aims at the target to emit laser pulses. The laser is reflected from the target and scattered in all directions. Part of the scattered light is returned to the sensor receiver, received by the optical system and imaged onto the avalanche photodiode. An avalanche photodiode is an optical sensor with an internal amplification function, so it can detect extremely weak optical signals and convert them into corresponding electrical signals. The contactless remote measurement can be realized by the high directionality, high monochromatism and high brightness of laser.