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Eddy current imaging is a relatively new technique of electromagnetic nondestructive testing that makes possible an accurate geometrical characterization of flaws. On contrary to the traditional approach to eddy current testing, spatially correlated information, that can be extracted from two‐dimensional eddy current images, is used to infer about flaw shape and dimensions. In general the problem of flaw reconstruction from the eddy current images belongs to the class of three‐dimensional nonlinear inverse problems. These problems can not be solved without properly chosen simplifications. In recent literature most of the authors tried to take advantage from the problem linearization. They used the eddy current image of a small diameter hole as a point spread function (two‐dimensional impulse response) and applied the classical linear filtering to deblur the image. Although this approach results in the restoration of the top view of the flaw it seems to be inadequate for full flaw reconstruction.

Discrete eigenvalues occur in eddy current problems in which the solution domain was truncated on its edge. In case of conductive material with a hole, the eigenvalues are complex numbers. Their computation consists of finding complex roots of a complex function that satisfies the electromagnetic interface conditions. The purpose of this paper is to present a method of computing complex eigenvalues that are roots of such a function.

The proposed approach involves precise determination of regions in which the roots are found and applying sets of initial points, as well as the Cauchy argument principle to calculate them.

The elaborated algorithm was implemented in Matlab and the obtained results were verified using Newton’s method and the fsolve procedure. Both in the case of magnetic and nonmagnetic materials, such a solution was the only one that did not skip any of the eigenvalues, obtaining the results in the shortest time.

The paper presents a new effective method of locating complex eigenvalues for analytical solutions of eddy current problems containing a conductive material with a hole.

A numerical model dedicated to external eddy current inspection of tubes has been developed using the volume integral method (VIM). The purpose of this paper is to suggest new discretization schemes based on non‐uniform B‐splines for the solution of the state equation with the method of moments (MoM).

VIM is a semi‐analytical approach providing fast and accurate results for the simulation of eddy current testing (ECT) of pieces with canonical geometries. The state equation derived with this formalism is solved using the Galerkin variant of the well‐known MoM.

This paper shows that an accuracy improvement is achieved in MoM by using B‐splines with degree 1 or 2 as projection functions in MoM instead of pulse functions. Moreover, comparisons between simulation results show that, for all ECT configurations tested, the use of degree 1 B‐splines is sufficient to get this improvement.

The use of B‐splines functions has already been proposed for MoM in the literature, but not in the framework of the Galerkin variant of MoM. This paper also shows quantitative comparisons between experiment and simulation as well as a study of the minimal degree required to get an accuracy improvement in MoM.

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.