Design of Liquid Level Sensor Based on Capacitance Detection

There are a lot of application requirements for liquid level measurement in engineering. At present, the formula of regular or uniform field is used in the calculation of the corresponding relationship between capacitance and liquid level of the capacitance liquid level sensor, which ignores the influence of the dispersion field on the capacitance distribution. There are some problems, such as unclear effective area of liquid level measurement and low accuracy of liquid level measurement. In order to further improve the accuracy of the sensor, the finite element method is used to simulate the electric field distribution of the capacitance sensor, analyze the influence of the dispersion field on the capacitance measurement, and carry out theoretical calculation and experimental verification, finally determine the effective measurement area of the liquid level. In this paper, a liquid level sensor which can be used in both conductive and nonconductive liquids is designed, which can save cost and achieve high sensitivity. Taking the conductive liquid as an example, the methods and suggestions to further improve the measurement accuracy of capacitive liquid level sensor are put forward.