Eur. Phys. J. AP 17, 25-28 (2002)
https://doi.org/10.1051/epjap:2001002

Lift-off and tilt effects on eddy current sensor measurements: a 3-D finite element study

Laboratoire de Génie Électrique de Paris (UMR 8507 CNRS) , SUPELEC, Universités de Paris XI et Paris VI, Plateau de Moulon, 91192 Gif-sur-Yvette Cedex, France

Corresponding author: yann.le-bihan@lgep.supelec.fr

Received: 25 January 2001
Revised: 12 July 2001
Accepted: 24 July 2001
Published online: 15 January 2002

Abstract

The eddy current sensor method is widely used to evaluate conductive parts. The eddy current measurements are very sensitive to the variations of the sensor positioning relatively to the part under evaluation, which can disturb consequently such evaluation. The effect of the variation of the positioning of a sensor having an U-shaped magnetic core has been studied by 3-D finite element computations. The results show that the tilt and the lift-off of the sensor relatively to the part under evaluation induce similar straight lines in the normalized impedance plane. Consequently their effect can be corrected fairly thanks to a single processing. This notably allows to reduce the sensor handling during its calibration as well as the calibration time.