DocumentCode :
988372
Title :
Analysis of the Liftoff Effect of Phase Spectra for Eddy Current Sensors
Author :
Yin, Wuliang ; Binns, Richard ; Dickinson, Stephen J. ; Davis, Claire ; Peyton, Anthony J.
Author_Institution :
Manchester Univ, Manchester
Volume :
56
Issue :
6
fYear :
2007
Firstpage :
2775
Lastpage :
2781
Abstract :
This paper presents an analytical model that 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 a sensor is virtually liftoff 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 a similar liftoff-independent property. Measurements made with a sample U-cored sensor next to plates of nonmagnetic and magnetic materials verified the theoretical results.
Keywords :
eddy current testing; electric sensing devices; double air-cored coil sensor; eddy current sensors; ferrite U-cored sensor; inductance change; liftoff effect analysis; nondestructive testing; numerical evaluations; phase signature; phase spectra; Analytical models; Coils; Current measurement; Eddy currents; Ferrites; Inductance; Magnetic materials; Magnetic sensors; Sensor phenomena and characterization; Testing; Electromagnetic (EM) sensor; liftoff; nondestructive testing; phase spectra; steel microstructure monitoring;
fLanguage :
English
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9456
Type :
jour
DOI :
10.1109/TIM.2007.908273
Filename :
4389153
Link To Document :
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