A semi-cylindrical capacitive sensor with signal conditioner for flow meter applications

Abstract

In this paper, a semi-cylindrical capacitive sensor with signal conditioner for flow meter applications is newly proposed. The numerical analysis method to calculate the capacitance of the semi-cylindrical capacitive sensor is analyzed and discussed. The pF-range capacitive variation of the semi-cylindrical capacitive sensor can be detected and converted into voltage variation by the signal conditioner. Besides, the signal conditioner is compact to simplify the circuit complexity, and could be easily implemented for flow meter applications. All the functions of the signal conditioner for flow meter applications are tested and proved through HSPICE simulation. Measurement results have successfully confirmed the correct functions and performance of the semi-cylindrical capacitive sensor with signal conditioner for flow meter applications, which ranges from 0.136 to 4.746 L/min, on the LCD panel coating machine.