AE/ultrasound detection system, and material monitoring apparatus and nondestructive inspection apparatus equipped the system
US7719689B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 17, 2007 |
| Grant date | May 18, 2010 |
| Priority date | — |
| Expiry date | Jun 9, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/02827
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
There is provided a system always capable of detecting AE/ultrasound received by an FBG, even when the FBG receives a change in temperature or strain and the Bragg wavelength is fluctuated. In the AE/ultrasound detection system, the reflected light from the FBG is caused to enter a Fabry-Perot filter having an FSR equal to or greater than the reflection wavelength band of the FBG. A change in the intensity of the transmitted light corresponds to the AE/ultrasound received by the FBG. Alternatively, the reflected light from FBG is caused to enter two Fabry-Perot filters having an FSR equal to or greater than the reflection wavelength band of the FBG and having the filter-transmittance peak wavelengths different from each other by FSR/4. The intensity of the transmitted light from each of the two Fabry-Perot filters is converted into a voltage signal, and the individual signals are subjected to addition and subtraction processes. Thus, a signal having a large amplitude corresponding to the AE/ultrasound received by the FBG can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.