| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 295371 | NDT & E International | 2011 | 5 Pages |
In the present study, two types of ferrite core probes were prepared with different pick-up coil positions for remote field eddy current testing. One probe has a pick-up coil on the beam of the U-type ferrite core, and the other probe has a pick-up coil on the pole of the U-type ferrite core. The two types of probes were examined for their capability to create an effective remote field to detect a back-side defect. The results showed that the pick-up coil at the pole of the U-type ferrite core can detect an effective remote field phenomenon. In addition a time harmonic analysis was carried out, and the flow of the magnetic flux of the direct field was used to analyze the difference in the results with the two probes.The detectability for back-side flaws was confirmed with the proposed probes. Compared to a previous study, the signal measured from back-side flaws with the type II probe was large. However, the signal-to-noise (SN) ratio for the detection of back-side flaws did not improve because of the different background signal before and after the back-side flaw.
Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Pick-up coil at the pole of the U-type ferrite core measured the effective remote field to detect the back-side flaw. ► FEA was successful in simulating the remote field phenomena. Analytical result of the relative permeability of 300 in good agreement with experimental results. ► Compared to a previous study, the phase change from the back-side flaw larger. SN ratio was not enhanced due to different background signal before and after the back-side flaw.
