The use of strain gauges can be divided into two methods. One method is to attach the strain gauge directly to the surface of a loaded component. This method is simple, but not sufficiently accurate. The other method is to attach the strain gauges to an elastic element to make a sensor, which is then loaded to establish a functional relationship between the load and the change in resistance. The measured load value is obtained by means of a pre-determined load calibration curve. The result is a more accurate measurement. The results obtained are more accurate.