Apparatus and method of checking the thickness and uniformity of a coating deposited on an elongated insulating body using a condenser sensor as part of a resonant electrical circuit

摘要

This invention concerns an apparatus for checking the thickness and uniformity of a coating made of conducting material deposited on an elongated insulating body, this apparatus comprising: a sensor sensitive to the presence of the elongated body and forming part of an electrical circuit powered by a power supply voltage (24), measurement instruments (25) to measure an electrical quantity that is a function of the thickness of the conducting coating, at the output of the circuit equipment for processing the electrical quantity to deduce the thickness of the conducting coating, wherein the sensor consists of a condenser (10) containing two plates separated from each other by an air gap containing a dielectric material, this condenser being adapted to enable the elongated body to pass through the air gap.