Design and realization of a capacitive sensor measurement system

Abstract

This paper's proposal is the design and realization of a new capacitive sensor measurement system focusing on micro-displacement on the basis of measuring principle of the variable pole pitch capacitance. First we design a capacitive sensor probe through theoretical calculation. In the second stage, we discuss the implementation of a digital measuring circuit and an efficient data acquisition system. Until now, most existing systems are too large, complex and inaccurate. But the proposed system in this paper can solve these problems. The end shows that this kind of micro-displacement capacitive sensor measurement system has good characteristics of response speed and high precision. A great deal of experimental data approve that the micro-displacement capacitive sensor measurement system's linearity is better than 0.39%, and the resolution can achieve 0.76% and the repeatability is 0.63μm.