A Sensor for Measuring the Tension of Cotton Belt

In this paper, the design process of a strain gauge sensor for measuring the tension of cotton belt is presented. The elastic body of the sensor is a single cantilever beam, and a light metal pulley is installed at the end of the beam. When the cotton belt passes through the pulley, the pulley will be subjected to pressure and cause the deformation of the beam. After processing, the electrical signals output by the resistance strain gauges pasted on the elastic body can be converted into the tension of the cotton belt. In this study, first of all, through mechanical calculation, it is determined that there is an approximate linear relationship between the change of the tension of the cotton belt and the output signal of the bridge of the elastomer. Then, through the finite element method, the relationship between the strain of the elastomer and the pressure on the guide wheel is analyzed, and the specific size of the elastomer and the appropriate position of the resistance strain gauge are determined. Finally, the temperature compensation and broken line correction are carried out. The practice shows that the measuring range of the sensor can reach 30N, the sensitivity can reach 2.35mV/V, the maximum linear speed of the 6 mm wide cotton belt passing through the guide wheel of the sensor can reach 2m/s, the working temperature range of the sensor is
$- 30\sim 60^{\circ }\text{C}$
, and the comprehensive measurement error is less than 0.5%F.S.