Strain gauge transducer types and working Principle
In this article we will learn about the strain gauge transducer types and working principle. We will also study about the advantages of strain gauge.
Strain gauge transducer types and working Principle
Strain gauge is a type of transducer which is used to measure Strain ( Linear or angular force) force.
working Principle of Strain gauge transducer
We know that metal resistance is directly proportional to its length, Hence whenever pull any metal ( Applied tensile force) or compress them ( Applied compress force) so change metal resistance from different reason.
1. Change in length
2. Change in diameter
3. Change in resistivity
By using a electric circuit we measure the changes of resistance and by use this also measure applied force
According figer when applied tensile force on metal his diameter varies from “D” to “d ” and their length also varies “L” to “l” so resistance are also varies from “R” to “r”
so gauge factor
GF = r/R divide by l/L
Type of strain gauge transducer
1. Unbounded type strain gauge
2. Bonded type strain gauge
3.Bonded metal foil strain gauge
4. Semiconductor Strain gauge
1. Wheatstone bridge strain gauge transducer
Unbound type strain gauge made from different material
1. Copper-Nickel
2. Chrome-Nickel
3. Nickel-Iron
In this material main quality available which is elasticity which means when force applied on metal length and diameter will change but remove this force its take his original position. It has four arms which connect like wheat stone bridge.
Wheatstone bridge condition
P/Q = R/S
where p q r s is resistance
Voltage E = 0 ( in balance condition)
when force applied on diaphragm unbalance create and resistance change so out put terminal get o/p volatile . which is strain force, ( this voltage is directly proportional to applied force ) . so voltmeter shows reading of applied force
2. Bonded type strain gauge
In bonded type strain gauge we use paper , bake light , teflon on grid element . it use like a base to protect from wire and also provide mechanical protection.
3. Bonded metal foil strain gauge
It is also type of Bonded type strain gauge but in this type strain gauge polymide or glass used as a grid base.
4. Semiconductor strain gauge
In semiconductor strain gauge silicon , germanium and other material used when applied force more resistivity changes become which used more force me can measure.
Advantage of semiconductor strain gauge
1. higher gauge factor
2. high sensitivity
3. Long life
4. Small size
5. Low cost
6. higher heat dissipation capacity
Hence these are strain gauge transducer types and working principle . We have also studied about the advantages of strain gauge Transducer.