Eddy current probe and method for flaw detection in metals
Abstract
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.
- Inventors:
- Issue Date:
- OSTI Identifier:
- 7003194
- Patent Number(s):
- 4675605 A
- Application Number:
- PPN: US 6-698369
- Assignee:
- SRI International, Menlo Park, CA (United States) PTO; EDB-94-125139
- DOE Contract Number:
- W-7405-ENG-82
- Resource Type:
- Patent
- Resource Relation:
- Patent File Date: 5 Feb 1985
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 42 ENGINEERING; EDDY CURRENT TESTING; PROBES; METALS; DEFECTS; DESIGN; ELECTRICAL INSULATORS; MATERIALS HANDLING EQUIPMENT; ELECTRICAL EQUIPMENT; ELECTROMAGNETIC TESTING; ELEMENTS; EQUIPMENT; MATERIALS TESTING; NONDESTRUCTIVE TESTING; TESTING; 420500* - Engineering- Materials Testing
Citation Formats
Watjen, J.P. Eddy current probe and method for flaw detection in metals. United States: N. p., 1987.
Web.
Watjen, J.P. Eddy current probe and method for flaw detection in metals. United States.
Watjen, J.P. Tue .
"Eddy current probe and method for flaw detection in metals". United States.
@article{osti_7003194,
title = {Eddy current probe and method for flaw detection in metals},
author = {Watjen, J.P.},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {6}
}