The strain gauge is a sensor that changes resistance with applied force; It measures physical quantities such as force, pressure, tension, and weight by converting them into changes in resistance. When external forces act on a fixed object, stress and strain are created. The reaction (to external forces) generated within the body is the stress, and the displacement and deformation generated is the strain.
Strain gauges are one of the most important sensors in electrical measurement technology for the measurement of mechanical quantities. As its name suggests, strain gauges are mainly used for strain measurement. As a technical term, "strain" includes tensile strain and compressive strain, distinguished by positive and negative symbols. Therefore, the strain gauge can measure both expansion and contraction.
The strain of a body is always caused by external or internal forces. Strain can be caused by force, pressure, moment, heat and changes in material structure. When certain conditions are met, the quantification degree or physical value of the influencing factor can be calculated through the measured dependent variable. This method is widely used in stress experimental analysis. Experimental stress analysis uses strain values measured on the surface of a specimen or structural part to describe the stress inside a material and to predict the safety and durability of the material. More specialized transmitters can be used to measure force or other derived physical quantities such as motion, pressure, acceleration, displacement and vibration. Such transmitters usually contain a pressure-sensitive diaphragm bonded to a strain gauge.
