Mapping of Eddy Current Probe Fields

Capobianco, T. E.; Fickett, F. R.; Moulder, John C.

doi:10.1007/978-1-4615-7763-8_73

Cited by 8 publications

(8 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Results obtained for two nominally identical air-core probes agreed very well with theoretical predictions for flaws in aluminum [5]. Differences in the flaw signals measured using these two probes were related to differing field intensities by direct magnetic field measurements, reported elsewhere [7]. For flaws in titanium specimens, poor agreement of theory and experiment was ascribed to inadequate sensitivity of the impedance-measuring instrument and to inadequate specimen thickness.…”

Section: Discussionsupporting

confidence: 73%

“…This year, two nominally identical air-core probes were used to study the uncertainty in flaw-signal measurements that results from variability in probe construction. In another related experiment [7], the magnetic fields of these probes were mapped and compared with theoretical calculations. Since most practical eddy current probes have a ferrite core, one ferrite-core probe was also used.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Semi-Elliptical Surface Flaw EC Interaction and Inversion: Experiment

Moulder

Gerlitz

Auld

et al. 1986

Review of Progress in Quantitative Nondestructive Evaluation

Self Cite

View full text Add to dashboard Cite

During recent years, rapid progress has been made in modeling the interaction of nonuniform eddy-current (EC) probe fields with surface flaws and verifying these models by comparisons with experiment. Following the development of the basic analysis for nonuniform probe fields [1], the first comparison of measured eddy current signals with predictions of the theory was made in 1983 [2]. The following year brought development of a full inversion procedure for rectangular flaws [3], which was successfully demonstrated using flaw signals measured for a series of rectangular electrical-discharge machined (EDM) notches in aluminum [4]. This year, in a companion paper [5], the model for interaction of nonuniform probe fields with flaws has been extended to semi-elliptical flaws. The present paper describes an extensive series of measurements of flaw signals for both fatigue cracks and semi-elliptical EDM notches in aluminum and titanium alloys. The measured flaw signals are compared with theoretical predictions and are also used to test the inversion procedure based on the theory [5]. EXPERIMENTThe objective of this study was to make a serjes of carefully controlled measurements of eddy current flaw signals for well characterized, semielliptical flaws in aluminum and titanium alloys to compare with flaw signals calculated using theoretical models described in a companion paper [5]. Both real fatigue cracks and EDM simulations were studied. Most measurements emphasized air-core probes, since the magnetic field distributions for these probes could be calculated using the theory of Dodd and Deeds [6]. One * Contribution of the National Bureau of Standards, not subject to copyright.

show abstract

Section: Discussionsupporting

confidence: 73%

mentioning

confidence: 99%

Semi-Elliptical Surface Flaw EC Interaction and Inversion: Experiment

Moulder

Gerlitz

Auld

et al. 1986

Review of Progress in Quantitative Nondestructive Evaluation

Self Cite

View full text Add to dashboard Cite

show abstract

“…Potential parameters or standards of comparison have included: a) probe responses to well characterized defects [2,3,4,5]; b) the decrease in defect response with probe lift-off and tilt [6]; c) the difference in probe impedance magnitude when the probe is in contact with aluminum and with titanium [7]; and d) the dimensions and strength of the probe field [7,8].…”

Section: Introductionmentioning

confidence: 99%

“…is one third the outside diameter of the core [9]. The ~ of an air core probe is somewhat larger than this relative to its physical dimensions [7]. Defect response magnitude is dependant not only on the relative dimensions of the probe and the defect, but also on the ratio of~ to the skin depth,…”

Section: Introductionmentioning

confidence: 99%

Coupling coefficient: a determinant of eddy current probe performance

1995

NDT & E International

View full text Add to dashboard Cite

“…These include electrical calibration with a small resistance in series with the probe to be calibrated [3], quantitative calibration by comparing theoretical calculations with measurements of either liftoff or EDM slots [3], and mapping of eddy current probe fields with magnetic field sensors such as SQUIDS, Hall probes, or search coils [4].…”

Section: Introductionmentioning

confidence: 99%