Three widely used full-bridge circuit arrangements are shown below. In the first two of these, for bending and direct stress, respectively, the number of active gages is expressed by . This value is substituted into Eq. ( 514.8 ) or Eq. ( 514.9 ) when calculating the calibration resistor to simulate a surface strain of . The physical arrangement of the gages is the same in both cases; but, as indicated by the equivalent-circuit diagrams, the gages are positioned differently in the bridge circuit to produce the desired signal in each instance.

Bending beam, with Poisson gage orientation: .



Uniform uniaxial stress, with Poisson gage orientation:

( continued ... )

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