Multi-frequency Eddy Current Testing using a GMR based instrument

The paper proposes the use of a suitable multi-frequency approach applied to a novel instrument for eddy current non-destructive testing on conductive materials. The instrument is composed by a smart eddy current probe, based on a Giant Magneto Resistance sensor, and by a suitable processing unit. Key features of the proposed instrument are the capability of detecting, locating, and characterizing thin defects such as superficial and sub-superficial cracks. The proposed multi-frequency solution, together with a suitable data processing, allow both the sensitivity in the defect detection to be increased and the ability to evaluate the defect characteristics in terms of shape and dimension to be improved.

[1]  Salvatore Calcagno,et al.  A novel approach for detecting and classifying defects in metallic plates , 2003 .

[2]  Feilu Luo,et al.  Reduction of Lift-Off Effects in Pulsed Eddy Current for Defect Classification , 2011, IEEE Transactions on Magnetics.

[3]  O Postolache,et al.  Using the skin effect to estimate cracks depths in mettalic structures , 2009, 2009 IEEE Instrumentation and Measurement Technology Conference.

[4]  D. Capriglione,et al.  Type a uncertainty in jitter measurements in communication networks , 2011, 2011 IEEE International Instrumentation and Measurement Technology Conference.

[5]  Gui Yun Tian,et al.  Defect depth estimation using pulsed eddy current with varied pulse width excitation , 2009 .

[6]  David Jiles,et al.  Review of magnetic methods for nondestructive evaluation (Part 2) , 1990 .

[7]  Luigi Ferrigno,et al.  GMR-based instrument for ECT on conductive planar specimens , 2010, 2010 IEEE Instrumentation & Measurement Technology Conference Proceedings.

[8]  Luigi Ferrigno,et al.  Crack Shape Reconstruction in Eddy Current Testing Using Machine Learning Systems for Regression , 2008, IEEE Transactions on Instrumentation and Measurement.

[9]  K. Miya,et al.  Nonlinear FEM-BEM formulation and model-free inversion procedure for reconstruction of cracks using pulse eddy currents , 2002 .

[10]  Yoshiaki Nagaya,et al.  Identification of multiple cracks from eddy-current testing signals with noise sources by image processing and inverse analysis , 2004 .

[11]  K. Miya,et al.  Reconstruction of cracks with physical closure from signals of eddy current testing , 2000 .

[12]  T. Uchimoto,et al.  Crack shape reconstruction in ferromagnetic materials using a novel fast numerical simulation method , 2004, IEEE Transactions on Magnetics.

[13]  Luigi Ferrigno,et al.  A New Digital Signal Processing Method for Spectrum Interference Monitoring , 2011 .

[14]  Junzhe Gao,et al.  Defect identification and classification of multi-frequency eddy current test based on spectrum method , 2010, The 2010 IEEE International Conference on Information and Automation.

[15]  C. Dolabdjian,et al.  Performance of Magnetic Pulsed-Eddy-Current System Using High Dynamic and High Linearity Improved Giant MagnetoResistance Magnetometer , 2006, IEEE Sensors Journal.

[16]  Zhiwei Zeng,et al.  Pulsed Eddy-Current Based Giant Magnetoresistive System for the Inspection of Aircraft Structures , 2010, IEEE Transactions on Magnetics.

[17]  Manfred R. Schroeder,et al.  Synthesis of low-peak-factor signals and binary sequences with low autocorrelation (Corresp.) , 1970, IEEE Trans. Inf. Theory.