A strain gauge is a sensor which resistance varies with applied force. It converts force, pressure, tension, weight or other parameter into electrical resistance which can be measured. When external force is applied to a stationary object, stress and strain are the results. Stress is defined as the object's internal resisting force and strain is defined as the displacement and deformation the occurs during stress process. Strain gauges are typically used to produce transducers or load cells for stress analysis (force, torsion, length, compression) and can be monoaxial, biaxial and triaxial depending on the field of application. Constatan and Karma alloys are most used materials used for strain gauges production.