( ... continued )

Combining Eqs. ( 514.3 ) and ( 514.4 ), and replacing , by , since there is no other resistance in the bridge arm,

Or,

  Eq. (514.5)

where is the strain (compressive) simulated by shunting with .

Solving for ,

Eq. (514.6) 

Since the simulated strain in this mode of shunt calibration is always negative, it is common practice in the strain gage field to omit the minus sign in front of the first term in Eq.(514.6), and write it as:

  Eq. (514.7) 

where is the simulated strain, in microstrain units.

When substituting into Eq. (514.7), the user must always remember to substitute the numerical value of the compressive strain, without the sign.

( continued ... )

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