Calculating Tensile Stress Using a Strain Gauge

[orla22]

A strain gauge has a unstrained resistance of 120 ohms, gauge factor of 2.0 is connected to steel girder so it experieces tensile stress. If strained resistance of gauge is 120.13 ohm. How do i calculate the tensile stress value?

 

[jasc15]

The Gauge Factor is the ratio of the resistance change to the strain change. In this case, the relative change of the resistance of the gauge is twice as large as the strain of the sample.