Analysis of the Lift-off Effect of Phase Spectra for Eddy Current Sensors

Author

Yin, W. ; Binns, R. ; Dickinson, S.J. ; Davis, C. ; Peyton, A.J.

Author_Institution

Dept. of Eng., Lancaster Univ.

Volume

3

fYear

2005

fDate

16-19 May 2005

Firstpage

1779

Lastpage

1784

Abstract

This paper presents an analytical model which describes the inductance change when a double air-cored coil sensor is placed next to a conducting plate. Analysis of the analytical model reveals that the phase signature of such sensor is virtually lift-off independent. This finding is verified by numerical evaluations. This paper also finds that the phase signature of a ferrite U-cored sensor can be approximated by that of a double air-cored sensor of similar size, and therefore possesses similar lift-off independent property. Measurements made with a sample U-cored sensor next to plates of non-magnetic and magnetic materials verified the theoretical results

Keywords

approximation theory; coils; eddy currents; magnetic cores; magnetic materials; magnetic variables measurement; spectral analysis; U-cored sensor; air-cored coil sensor; analytical model; conducting plate; eddy current sensors; inductance change; lift-off effect; magnetic materials; nonmagnetic materials; phase signature; phase spectra; Analytical models; Coils; Current measurement; Eddy currents; Ferrites; Inductance; Magnetic materials; Magnetic sensors; Sensor phenomena and characterization; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Instrumentation and Measurement Technology Conference, 2005. IMTC 2005. Proceedings of the IEEE

Conference_Location

Ottawa, Ont.

Print_ISBN

0-7803-8879-8

Type

conf

DOI

10.1109/IMTC.2005.1604477

Filename

1604477