Gauge Factor Calculator : Strain Factor of a Strain Gauge
Posted by Dinesh onGauge factor (GF) or strain factor of a strain gauge is the ratio of relative change in electrical resistance R, to the mechanical strain ε.
Gauge factor is defined as the ratio of per unit change in resistance to per unit change in length.
The strain is usually expressed in terms of microstrain. 1 microstrain = 1 μm/m.
| Material | Gauge Factor |
|---|---|
| Metal foil strain gauge | 2-5 |
| Thin-film metal (e.g. constantan) | 2 |
| Single crystal silicon | -125 to + 200 |
| Polysilicon | ±30 |
| Thick-film resistors | 100 |
| p-type Ge | 102 |
Formula:
where,
ΔR = change in resistance caused by strain
ΔG = resistance of the undeformed gauge
ε = strain
GF = gauge factor
ΔR = change in resistance caused by strain
ΔG = resistance of the undeformed gauge
ε = strain
GF = gauge factor