Material condition assessment with spatially periodic field sensors
US6657429B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2000 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | Sep 20, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Inductive sensors measure the near surface properties of conducting magnetic materials. The sensors generally include parallel winding segments to induce a spatially periodic magnetic field in a material under test. The sensors may provide a directionally dependent measure with measurements made in varying orientations of the sensor with respect to the material property variation directions. The sensors may be thin, conformable sensors that can be mounted on a test material and, for example, monitor crack initiation under the sensor. A second sensor may be left in air to provide a reference measurement, or the temperature of the material under test can be varied to verify the response of the individual sensing elements. Sensors can be mounted to materials under test in order to not modify the environment that is causing the stress being monitored. A sensor may be flexible to conform to the shape of the surface of the material under test and may be mounted in difficult to access locations such as around fasteners of an aircraft. Spatially periodic field eddy current sensors may be scanned across a material to create images of the absolute material property beneath the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.