Eddy current probe and method for flaw detection in metals
A flaw detecting system is shown which includes a probe having a pair of ferrite cores with in-line gaps in close proximity to each other. An insulating, non-magnetic, non-conducting holder fills the gaps and supports the ferrite cores in a manner such that the cores form a generally V-shape. Each core is provided with an excitation winding and a detection winding. The excitation windings are connected in series or parallel with an rf port for connection thereof to a radio frequency source. The detection windings, which are differentially wound, are connected in series circuit to a detector port for connection to a voltage measuring instrument. The ferrite cores at the in-line gaps directly engage the metal surface of a test piece, and the probe is scanned along the test piece. In the presence of a flaw in the metal surface the detection winding voltages are unbalanced, and the unbalance is detected by the voltage measuring instrument. The insulating holder is provided with a profile which conforms to that of a prominent feature of the test piece to facilitate movement of the probe along the feature, typically an edge or a corner. 9 figs.
- DOE Contract Number:
- W-7405-ENG-82
- Assignee:
- SRI International, Menlo Park, CA (United States)
- Patent Number(s):
- A; US 4675605
- Application Number:
- PPN: US 6-698369
- OSTI ID:
- 7003194
- Country of Publication:
- United States
- Language:
- English
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