Version 1
: Received: 6 November 2020 / Approved: 9 November 2020 / Online: 9 November 2020 (11:11:44 CET)
How to cite:
Meng, X.; Lu, M.; Yin, W.; Bennecer, A.; Kirk, K. Inversion of Lift-Off Distance and Thickness for Non-Magnetic Metal Using Eddy Current Testing. Preprints2020, 2020110278. https://doi.org/10.20944/preprints202011.0278.v1
Meng, X.; Lu, M.; Yin, W.; Bennecer, A.; Kirk, K. Inversion of Lift-Off Distance and Thickness for Non-Magnetic Metal Using Eddy Current Testing. Preprints 2020, 2020110278. https://doi.org/10.20944/preprints202011.0278.v1
Meng, X.; Lu, M.; Yin, W.; Bennecer, A.; Kirk, K. Inversion of Lift-Off Distance and Thickness for Non-Magnetic Metal Using Eddy Current Testing. Preprints2020, 2020110278. https://doi.org/10.20944/preprints202011.0278.v1
APA Style
Meng, X., Lu, M., Yin, W., Bennecer, A., & Kirk, K. (2020). Inversion of Lift-Off Distance and Thickness for Non-Magnetic Metal Using Eddy Current Testing. Preprints. https://doi.org/10.20944/preprints202011.0278.v1
Chicago/Turabian Style
Meng, X., Abdeldjalil Bennecer and Katherine Kirk. 2020 "Inversion of Lift-Off Distance and Thickness for Non-Magnetic Metal Using Eddy Current Testing" Preprints. https://doi.org/10.20944/preprints202011.0278.v1
Abstract
For the electromagnetic eddy current testing, various methods have been proposed for reducing the lift-off error on the measurement of samples. In this paper, instead of eliminating the measurement error caused by the lift-off effect, an algorithm has been proposed to directly measure the lift-off distance between the sensor and non-magnetic conductive plates. The algorithm is based on a sample-independent inductance (SII) feature. That is, under high working frequencies, the inductance is found sensitive to the lift-off distance and independent of the test piece under an optimal single high working frequency (43.87 kHz). Furthermore, the predicted lift-off distance is used for the thickness prediction of the non-magnetic conductive samples using an iterative method. Considering the eddy current skin depth, the thickness prediction is operated under a single lower frequency (0.20 kHz). As the inductance has different sensitivities to the lift-off and thickness, the prediction error of the sample thickness is different from that of the lift-off distance. From the experiments on three different nonmagnetic samples – aluminium, copper, and brass, the maximum prediction error of the lift-off distance and sample thickness is 1.1 mm and 5.42 % respectively at the lift-off of 12.0 mm.
Keywords
Eddy current sensor; lift-off measurement; thickness measurement; non-destructive testing; sample-independence.
Subject
Engineering, Automotive Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
