Bragg grating pressure sensor for industrial sensing applications
US6776045B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 2001 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Nov 8, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L11/025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fiber grating pressure sensor for use in an industrial process includes an optical sensing element 20,600 which includes an optical fiber 10 having a Bragg grating 12 impressed therein which is encased within and fused to at least a portion of a glass capillary tube 20 and/or a large diameter waveguide grating 600 having a core and a wide cladding and which has an outer transverse dimension of at least 0.3 mm. Light 14 is incident on the grating 12 and light 16 is reflected from the grating 12 at a reflection wavelength &lgr;1. The sensing element 20,600 may be used by itself as a sensor or located within a housing 48,60,90,270,300. When external pressure P increases, the grating 12 is compressed and the reflection wavelength &lgr;1 changes. The shape of the sensing element 20,600 may have other geometries, e.g., a “dogbone” shape, so as to enhance the sensitivity of shift in &lgr;1 due to applied external pressure and may be fused to an outer shell 50. A temperature grating 270 may be used to measure temperature and allow for a temperature-corrected pressure measurement. The sensor may be suspended within an outer housing 112, by a fluid, spacers, or other means. The…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.