Strain gauge || what is strain gauge ? || Working principle of strain gauge || Example-types of strain gauge

what is strain gauge ?

A string gauge is a sensor which whose resistance varies with applied force.it converts force, pressure, tension weight e.t.c in to a Electrical resistance which can then be measured like pizo resistive transducer.

Working principle of strain gauge :

As we applied forced to extend the length of gauge it's cross section area must reduce becouse volume of material remain constant.

Then strain gauge is connected to a balanced whiston  bridge but as force is applied on gauge resistance change and bridge becomes unbalanced producing V0

                     

Gauge factor Gf=1+2Y

Y= paison ratio

Using gauge factor we determined change in resistance to the modify resistance and then using Wheaton bridge V0

Examples :

Gauge factor in semiconductor is 120

Gauge factor in Ni=12

Gauge factor in co=4.9

Gauge factor in pt=5.2

C=10

types of strain gauge

1. Straight strain checks. 

2. Layer Rosette strain checks. 

3. Twofold straight strain checks. 

4. Full extension strain checks. 

5. Shear strain measures. 

6. Half extension strain checks. 

7. Section strain checks. 

8. 45°-Rosette (3 estimating bearings)

application of strain gauge

Strain checks are utilized for some applications. They are regularly utilized inside different sensors to quantify the strain or stress.  This implies they can gauge changes in power, strain, weight and pressure by giving a change in electrical resistance.

measuring strain 

Since the course of strain estimations has been set up, the subsequent stage when utilizing strain measures is getting helpful data .The strain check should be associated with an electrical circuit that is able to do precisely reacting to the moment changes in opposition related with strain.

 Numerous strain checks can be utilized in a separated extension circuit to quantify little changes in electrical obstruction. This is known as a Wheatstone span. In a Wheatstone span setup, an excitation voltage is applied across the circuit, and the yield voltage is estimated across two focuses in the scaffold. When there is no heap following up on the heap cell, the Wheatstone span is adjusted and there is zero yield voltage.

 Any little change in the material under the strain measure brings about an adjustment of the obstruction of the strain check as it twists with the material. This makes the scaffold be tossed out of equilibrium, bringing about an adjustment of the yield voltage. As expressed before, the opposition change is minute, which implies that signal enhancement is frequently expected to appropriately decide changes. The intensification interaction reinforces the strain signal changes; be that as it may, it likewise prompts more undesirable clamor additionally being recognized in the sign. Signal molding sift through the abundance clamor, guaranteeing precise and reasonable information.