Fiberoptic pressure sensor having drift correction means for insitu calibration
US5422478A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1994 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Sep 28, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/3845
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved intensity-encoded fiber optic sensor incorporating novel drift correction and filtering means is disclosed. The first embodiments of the invention relate to means for removing unwanted higher-order core and cladding modes from an intensity-encoded signal in an optical fiber using mode strippers and mode filters located strategically at various points in the sensing system. The second set of improvements in the invention relate to an improved technique for long-term temporal drift cancellation in a fiber optic pressure sensor by periodically applying pressure to the sensor tip in order to ascertain the measured voltage at which the sensor diaphragm contacts other elements of the sensor. This measured voltage is subtracted from an initial calibration voltage, and the result is applied to the measured signal as a constant correction term.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.