Definition - What does Strain Gauge mean?
A strain gauge is a measurement device that is used to quantify the amount of deformation that a material undergoes when a stress is applied to it. The strain gauge quantifies this measurement by dividing the deformed length of the material by the original length of the material.
Although knowing the amount of stress a material can handle is important to determine a material's strength, it does not tell much about the material's ductility. A strain gauge helps determine a material's ductility and is an important tool that is used to quantify a material's ability to plastically deform.
Corrosionpedia explains Strain Gauge
A strain gauge can measure both compressive and tensile stresses. Strain gauges are commonly used in conjunction with tensile and compression testing so that both the stress applied to a material and the strain is captured. This allows testing personnel to create a stress-strain curve, which is commonly used in material science.
Strain can be measured by graduations on the gauge itself. However, newer strain gauges are electronic. These electronic gauges are calibrated and wired into a computer system, which captures the signals sent from the strain gauge and plots them on a graph.