The strain gauge sensor is a functional component that converts a force into an electrical signal by a metal elastomer, and generally consists of a resistance strain gauge, an elastomer, and a transmission circuit. It is a Wheatstone bridge circuit consisting of a resistance strain gauge mounted on an elastomer-sensitive surface. Under the excitation of an external power supply, it realizes a force-sensitive transformation of four transformations: force-strain-resistance-electrical signal change. sensor. The basic working principle of the resistance strain sensor is the elastic Hooke's law of the elastomer, the strain-resistance effect of the resistance strain gauge and the Wheatstone bridge principle.
The resistance strain type pressure sensor is a sensor that combines a star-receiving circuit composed of a resistance strain gauge and an elastic sensing element. When the elastic sensitive element is subjected to pressure, strain will be generated, and the strain gauge attached to the surface will also generate strain, which is manifested as a change in the resistance value. Thus, the deformation of the elastomer is converted into a change in the resistance strain gauge. The four resistance strain gauges are connected in a bridge manner, and a certain voltage value is applied to the two input ends, and the common mode voltage outputted by the two output terminals increases or decreases with the change of the resistance value on the bridge. Generally, the correspondence of such changes has an approximately linear relationship. By finding the correspondence between the pressure change and the output common mode voltage change, the pressure value can be obtained by measuring the common mode voltage.
1, high resolution, can detect very small strain, such as 1-2 micro strain;
2, the error is small, generally less than 1%;
3. Small size and light weight.
4, the measurement range is large, from elastic deformation can be measured to plastic deformation (1-2%), up to 20%;
5, can measure static, but also measure rapid alternating stress;
6. Have all the advantages of electrical measurement, such as measurement results for easy transmission, recording and processing;
7, can work in a variety of harsh environments. Such as from the universe vacuum to thousands of atmospheres; from near absolute zero temperature to nearly 1000 ° C high temperature; centrifugal acceleration can reach hundreds of thousands of "g"; under the conditions of vibration, magnetic field, radioactivity, chemical corrosion, etc., as long as appropriate measures are taken, Can also work reliably;
8, low prices, variety, easy to choose and use.
The resistance strain sensor has complex structure, fluctuating functions, convenient operation, high sensitivity and fast response, and is commonly used in aviation, machinery, electric power, chemical industry, construction, and the like. Secondly, it should include a resistance strain sensor, a potentiometer sensor, and the like. The foil grid in the foil strain gauge is made of metal foil by photolithography, etching and the like. The information of the foil is mostly a copper-nickel alloy with high electrical resistivity and good thermal fluctuation. The contact area of the foil strain gauge and the base is much larger, the heat dissipation condition is better, the creep is smaller during the long time measurement, and the divergence is better, which is suitable for mass consumption.