A new differential eddy current testing sensor used for detecting crack extension direction

In this paper a new differential eddy current testing sensor is proposed which is composed of two planar circumferential gradient winding spiral coils. The eddy current testing sensor can detect out the existence of crack in conductive material surface and furthermore the crack extension direction because of the circumferential gradient winding spiral structure of coil. We study the detection principle of crack extension direction and carry out experimental test. The test results show that the impedance of circumferential gradient winding coil mainly varies with crack extension direction and width. Based on impedance plane analysis we extract the features which can indicate the crack characteristics and study on the inverse quantitative evaluation of crack extension direction and crack width.

[1]  M. Ruch,et al.  Calculation and simulation of impedance diagrams of planar rectangular spiral coils for eddy current testing , 2006 .

[2]  P. Dular,et al.  A perturbation approach for the modelling of eddy current nondestructive testing problems with differential probes , 2006, 2006 12th Biennial IEEE Conference on Electromagnetic Field Computation.

[3]  R. J. Ditchburn,et al.  Planar rectangular spiral coils in eddy-current non-destructive inspection , 2005 .

[4]  K. Kawabe,et al.  Planar inductor , 1984 .

[5]  Gui Yun Tian,et al.  Reduction of lift-off effects for pulsed eddy current NDT , 2005 .

[6]  S. Tumański.  Induction coil sensors—a review , 2007 .

[7]  Peng Xu,et al.  Differential eddy current testing sensor composed of double gradient winding coils for crack detection , 2010, 2010 IEEE Sensors Applications Symposium (SAS).

[8]  Sotoshi Yamada,et al.  Eddy current testing probe composed of planar coils , 1995 .

[9]  Sotoshi Yamada,et al.  Defect images by planar ECT probe of meander-mesh coils , 1996 .

[10]  Masato Enokizono,et al.  Crack detection and recognition using an eddy current differential probe , 1999 .

[11]  E. Kriezis,et al.  Eddy currents: theory and applications , 1992, Proc. IEEE.

[12]  Sung-Jin Song,et al.  Eddy current flaw characterization in tubes by neural networks and finite element modeling , 2000 .

[13]  Theodoros Theodoulidis,et al.  Impedance evaluation of rectangular coils for eddy current testing of planar media , 2002 .

[14]  Gui Yun Tian,et al.  A FEATURE EXTRACTION TECHNIQUE BASED ON PRINCIPAL COMPONENT ANALYSIS FOR PULSED EDDY CURRENT NDT , 2003 .

[15]  Li Shu,et al.  Study of pulse eddy current probes detecting cracks extending in all directions , 2008 .

[16]  R. W. Baines,et al.  The research of inhomogeneity in eddy current sensors , 1998 .

[17]  B. Helifa,et al.  Detection and measurement of surface cracks in ferromagnetic materials using eddy current testing , 2006 .

[18]  Huang Songling,et al.  Development of differential probes in pulsed eddy current testing for noise suppression , 2007 .

[19]  Masato Enokizono,et al.  A detection of backside crack using rotational magnetic flux sensor with search coils , 1996 .

[20]  J. Rudlin,et al.  Multiple sensors on pulsed eddy-current detection for 3-D subsurface crack assessment , 2005, IEEE Sensors Journal.

[21]  H.G. Ramos,et al.  Eddy Current Testing of Conductive Materials , 2008, 2008 IEEE Instrumentation and Measurement Technology Conference.

[22]  Masato Enokizono,et al.  Defect size and shape determination by moving magnetic field type sensor , 1998 .

[23]  Peng Xu,et al.  Eddy Current Testing Probe Composed of Double Uneven Step Distributing Planar Coils for Crack Detection , 2008 .

[24]  Gui Yun Tian,et al.  Wavelet-based PCA defect classification and quantification for pulsed eddy current NDT , 2005 .