Gravity and differential gravity sensor, and system and method for monitoring reservoirs using same
US6671057B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 31, 2001 |
| Grant date | Dec 30, 2003 |
| Priority date | — |
| Expiry date | Apr 18, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B9/02097
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A gravity sensor is disclosed which includes a first mass adapted to free fall when selectively released from an initial position. The mass has optical elements adapted to change a length of an optical path in response to movement of the mass. The sensor output is coupled to a beam splitter. One output of the splitter is coupled substantially optically directly to an interferometer. Another output of the splitter is coupled to the interferometer through an optical delay line. A frequency of the interference pattern is directly related to gravity at the mass. A second such mass having similar optics, optically coupled in series to the first mass and adapted to change the path length in opposed sign, when selectively dropped to cause time coincident movement of the two masses, generates an interference pattern having frequency related to gravity difference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.