Patent ID: 7262867
Filing Date: 2007-08-28
Classification: G01B

Abstract:
1. A device for contact free measurement of the thickness of a thin layer coated on a substrate, the device comprising: a measuring head including optical means for measuring the thickness of the thin layer coated on the substrate, said optical means measuring the transparency of the substrate and of the relative layer applied to the substrate, said optical means including an optical transmitter and an optical receiver, said optical transmitter and said optical receiver being arranged on opposite sides of said substrate, said optical transmitter and said optical receiver measuring attenuation of an optical signal passing through the substrate, said head comprising surface resistivity means for measuring the thickness of the thin layer coated on the substrate through surface resistivity, said surface resistivity means comprising a transmitter with a transmission coil and a receiver with a receiver coil, said transmitter producing an electromagnetic field, said receiver detecting the electromagnetic field emitted by said transmission coil, said receiver and said transmitter measuring attenuation of said electromagnetic field when electromagnetic field passes through the substrate, said transmitter coil and said receiver coil being arranged on opposite sides of said substrate, the substrate passing between said transmission coil and said receiving coil, said optical transmitter being arranged coaxially with said transmission coil, said optical receiver being coaxially arranged with said receiving coil.