Eddy current surface inspection probe for aircraft fastener inspection, and inspection method
US5510709A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1995 |
| Grant date | Apr 23, 1996 |
| Priority date | — |
| Expiry date | Apr 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/9013
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An eddy current surface inspection array probe and method for detecting cracks and flaws in aircraft skin metal immediately surrounding rivets, without requiring rivet removal or manual scanning. The array probe includes a circular array of small sense coils positioned beneath a much larger drive coil encased in ferrite. The sense coils are differentially connected in pairs such that the signals from two sense coils located on opposite sides of the rivet (180.degree. apart) subtract to produce a resultant output signal. During operation, the probe is positioned concentrically over the rivet and data acquired from all sense coil pairs. If no cracks or other defects are present, all sense coil pairs produce a null (zero) signal. If a crack exists, some sense coil pairs (the exact number depending on the crack length, number of sense coils, and sense coil spacing) produce a non-zero signal. The probe and method can be employed to inspect a variety of other structural features which are nominally circularly symmetrical.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.