Abstract
Single frequency phase analysis eddy current techniques have limited potential for inspections for surface cracking in inhomogeneous ferromagnetic welded surfaces [1). Signals from these cracks are masked in noise produced by lift-off, probe wobble and local changes of the permeability of the weld, the most troublesome noise source. Surface cracks and changes in magnetic permeability create signals with phase angles that are too close to be discriminated from each other. Another method, in addition to phase discrimination, must be used to distinguish crack signals from signals created by changes in magnetic permeability. This paper explores the use of the comparison of phase and amplitude data from two probe frequencies to distinguish cracks from changes in local magnetic permeability.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
P. Holler, R. Becker, and R. S. Sharpe, “The Application of Eddy Currents in Weld Testing, ” Welding in the World, 22 (1984).
H.L. Libby, Introduction to Electromagnetic Nondestructive Test Methods (Robert E. Kreiger, Huntington, NY, 1971 ).
F.G. Stremler, Introduction to Communication Systems (Addison-Wesley, Reading, MA, 1982 ).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1990 Springer Science+Business Media New York
About this chapter
Cite this chapter
Gilstad, C.W., Dersch, M.F., Denale, R. (1990). Multi-Frequency Eddy Current Testing of Ferromagnetic Welds. In: Thompson, D.O., Chimenti, D.E. (eds) Review of Progress in Quantitative Nondestructive Evaluation. Review of Progress in Quantitative Nondestructive Evaluation. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-5772-8_175
Download citation
DOI: https://doi.org/10.1007/978-1-4684-5772-8_175
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4684-5774-2
Online ISBN: 978-1-4684-5772-8
eBook Packages: Springer Book Archive