In this note, we are going to learn about the Gauge Factor of a strain gauge. Also, the Formula of the gauge factor and its values. Welcome to Poly Notes Hub, a leading destination for polytechnic engineering notes.

Author Name: Arun Paul.

What is Gauge Factor?

Gauge factor (GF) is the ratio of relative change in electrical resistance to the mechanical strain.

Formula of Gauge Factor:

Where:

• ΔR = Change in resistance
• R = Original resistance
• ε = Strain

Gauge Factor Range of Metal and Semiconductor Strain Gauge

Type of Strain Gauge	Gauge Factor (GF) Range	Description
Metal Strain Gauge	2 – 5	Commonly used strain gauge made from metallic alloys like constantan or nichrome. It has good stability and moderate sensitivity.
Semiconductor Strain Gauge	50 – 200	Made from semiconductor materials like silicon or germanium. It has very high sensitivity but is more affected by temperature changes.