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Wheatstone Bridge Output & Nonlinearity

Four Active Gages

Description (Note 1)     Four active gages in uniaxial stress field--two aligned with maximum principal strain, the other two with transverse "Poisson" strain (column).

Output Equation (Note 2)     mV/V ( Nonlinear )

Nonlinearity    

Actual Strain    

where:

  = Poisson's ratio of the strained material
  = gage factor of both gage and instrument
  = actual strain, in uniaxial tension or compression, in the axial direction
  = total strain indicated by the strain gage instrument
  = uncorrected axial strain


Note 1 : The resistance of each arm in a branch between the power corners of the bridge is nominally the same for both arms.
Note 2 : A constant-voltage power supply is assumed. Both and are expressed in microstrain units.