Pressure transducer apparatus
US4942767A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1989 |
| Grant date | Jul 24, 1990 |
| Priority date | — |
| Expiry date | Jun 2, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R23/008
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A micromachined diaphragm is positioned across a gap from an end of an optic fiber. The optic fiber and the diaphragm are integrally mounted. The end of the optic fiber provides a local reference plane which splits light carried through the fiber toward the diaphragm. The light is split into a transmitted part which is subsequently reflected from the diaphragm, and a locally reflected part which interferes with the subsequently diaphragm reflected part. The interference of the two reflective parts forms an interference light pattern carried back through the fiber to a light detector. The interference pattern provides an indication of diaphragm deflection as a function of applied pressure across the exposed side of the diaphragm. A detection of magnitude and direction of diaphragm deflection is provided by use of a second fiber positioned across the gap from the diaphragm. The second fiber provides an interference pattern in the same manner as the first fiber but with a phase shift. An opening allowing communication between ambient and the gap enables use of the interferometer sensor as a shear stress measuring device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.