The design of film thickness measure system based on capacitance sensor

According to the practical needs, a film thickness measure system based on capacitance sensor are designed integrated with the features of this kind of sensor. In this thesis, first analyzed the measure principle of capacitance sensor, and introduced the each component of this system, following elaborated working principle of high precision capacitance/ voltage converter IC CAV444 and its circuit design, at last, displayed the result of the overall test. The results showed this system can well measure the film thickness with the Precision higher than 1 um, and can be widely used in online inspection of non-metallic material.