Determination of the length of cracks by characteristic points of the eddy current probe signal distribution

Keywords

eddy current method, eddy current probe, crack length, spatial distribution of the signal from the defect, sensitivity threshold.

Cite as

Uchanin V. M. Determination of the length of cracks by characteristic points of the eddy current probe signal distribution. Physicochemical Mechanics of Materials. 2025. 61(6), 084-090.

https://doi.org/10.15407/pcmm2025.06.084

Abstract

The traditional procedure for determining the length of detected cracks using eddy current probe signals is analyzed and possible errors in determining the crack length associated with the scanning step and the installed level of the sensitivity threshold of the eddy current flaw detector are analyzed. A perspective method for determining the length of cracks using characteristic points of the spatial distribution of the signal amplitude in the direction along the crack, which is invariant with respect to the installed sensitivity level, is presented and investigated. Such characteristic points are the inflection points for the first derivative of the signal distribution or the points of minimum for the distribution of the second derivative of the signal distribution. Effective implementation of the proposed method can be used in automated eddy current inspection systems with line-by-line scanning of the inspected surface with obtained result recording and subsequent processing.

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