Design of Differential Cylindrical Capacitive Displacement Sensor

Abstract

This paper deals with the design of a differential cylindrical capacitive displacement sensor. It consists of four main conductance cylinders that form two capacitors. Their capacitances vary with controlling cylinder displacement. The controlling cylinder has two main parts: a lower part which is the ground shielded and an unshielded upper part. Capacitive measuring electronic circuit is designed to eliminate the effect of parasitic capacitances and simulated in the PSpice program. The relationship between displacement and output voltage is linear and the sensitivity is doubled compared with a single-ended capacitive displacement sensor.

Keywords

• sensors
• displacement
• capacitive
• cylindrical
• differential