Fiber optic acoustic emission sensor
US6289143A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1998 |
| Grant date | Sep 11, 2001 |
| Priority date | — |
| Expiry date | Apr 2, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/29359
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A fiber optic acoustic emission (FOAE) sensor particularly suitable for vibration sensing in a hostile environment has a pair of optical fibers each having an end face. In one embodiment, a hollow tube or core having opposite open ends receives the end faces of the optical fibers. Means are provided for fixing the optical fibers in the hollow core with the end faces facing each other and spaced by a distance from each other in the core. A signal processing unit is connected to the optical fibers for supplying light to, and for receiving light from, the optical fibers and for measuring variations in optical phase which result in changes in the light intensity due to vibrations of the hollow core. The hollow core is fixed in a resonant cylinder, and the resonant cylinder is fixed in a housing to complete the sensor. Other embodiments dispense with the need for the hollow tube or core and employ means for fixing the optical fibers within a precision hole, advantageously produced by electrical discharge machining (EDM) or similar processes, provided in the resonant cylinder. A system employing these embodiments of the FOAE sensor is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.