Strain gauge is a device used to measure strain on an object. A strain is a normalized measure of deformation representing the displacement between particles in the body relative to a reference length. Strain measures how much a given deformation differs locally from a rigid-body deformation.
Gauge factor (GF) or strain factor of a strain gauge is the ratio of relative change in electrical resistance R, to the mechanical strain.
|GF||Gauge factor (dimensionless)|
|DR||The change in resistance caused by strain (ohm)|
|RG||The resistance of the undeformed gauge (ohm)|
|ϵ||The strain (absolute change in length/original length) (dimensionless)|