THICKNESS MEASUREMENT OF A NONMAGNETIC METALLIC PLATE USING HARMONIC EDDY CURRENT EXCITATION AND A GMR SENSOR

A. Lopes Ribeiro, Helena G. Ramos, J. Couto Arez

Abstract

This paper describes the implementation of a device that measures the thickness of metallic plates. A pancake coil for magnetic field sinusoidal excitation is used and detection is performed with a bridge giant magneto-resistor sensor. The paper uses the theory of the linear transformer to explain the liftoff effect with a special attention to the point of intersection phenomenon.

Keywords

eddy currents, giant magneto-resistor sensor, liftoff, linear transformer theory

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IMEKO-TC4-2011-064.pdf

DOI

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IMEKO TC

TC4 - Measurement of Electrical Quantities

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