Apparatus for the measurement of gravitational fields
US5962781A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 1997 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Jun 13, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V7/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus for measuring gravitational fields comprising a superconducting string (1) fixed at both ends and forming part of a closed superconducting loop inductively coupled to two driving solenoids (L.sub.d1, L.sub.d2). Displacement of the string in response to a gravitational field is sensed by two magnetic flux transformers each comprising a signal coil and two pick-up coils ((L.sub.p1, L.sub.p2). Pairs of pick-up coils lie in two perpendicular planes providing two independent channels of measurements. The two arms of each flux transformer are balanced to convert only the amplitudes of the string's antisymmetric natural modes into an output voltage. The output voltage of each channel is used to produce a feed-back current distribution (L.sub.y1, L.sub.y2) proximate and parallel to the string. By adjusting the feed-back current, the effective relaxation time and resonant frequency of the first antisymmetric mode of the string can be adjusted, while leaving the symmetric modes unchanged, thus increasing the apparatus' sensitivity to gravity gradients.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.