Investigation on capacitive force measuring device with linear output

Capacitive force measuring device is the most precise of all electrical force force measuring devices with its extremely high sensitivity and resolution. The shape of the capacitive electrode had an important influence on the output of the capacitive force measuring device, and a capacitive force measuring device with linear output could be obtained by regulating the shape of the electrode. The functional conditions that the shape of the capacitor electrode needed to meet when the force measuring device had been linearly output are obtained through theoretical analysis. The output characteristics of two electrode shapes satisfying linear output had been studied through the method of combining theoretical analysis and experiment. Results shown that when the electrode shape satisfied the function condition, the experimental data output of the force measuring device had a good linear relationship, and the linearity could reach more than 0.99. The value of the constant term in the electrode shape function had almost no influence on the output linearity of the force measuring device, but had a direct influence on the slope and intercept of the linear output. For the electrodes with a certain shape, the applied voltage only affected the output range of the force measuring device and did not affect its output linearity. The wide range and high-accuracy measurement of the force measuring device could be realized by using the capacitive force measuring device with linear output with setting different fixed-value loading voltages.