Errors Due to Leadwire Resistance
|The resistance of leadwires in series with an active strain
gage attenuates the bridge output (or "desensitizes" the gage) by
= total resistance of leadwires in series with the gage (two lengths of leadwire for a two-wire-circuit, and one length for a three-wire circuit)
= gage resistance.
The error, e , caused by leadwire resistance can be expressed as:
When the leadwire resistance is known , indicated strains can be corrected for leadwire effects by multiplying the strains by:
As an alternative to correcting the data numerically, the gage factor of the strain indicator can be adjusted from its original value, , to a new, compensating value, , where .