Apparatus for reducing noise due to sensor vibration during measurement of a weak magnetic field
US5686836A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1995 |
| Grant date | Nov 11, 1997 |
| Priority date | — |
| Expiry date | Sep 12, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/028
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for measuring a weak magnetic field in a background D.C. magnetic field such as the earth's magnetic field or the like includes a magnetic pickup portion that is supported by a support mechanism which does not impede minute movement in the x- and y-axis direction. A pair of A.C. linear gradient magnetic fields whose directions of gradients are parallel to the x-axis and y-axis, respectively, are used for obtaining reference signals for sensing the position of the pickup portion. The frequencies of the A.C. linear gradient magnetic fields are set to be sufficiently higher than the frequency of the weak magnetic field that is to be measured. The A.C. linear gradient magnetic fields are provided by A.C. current flowing in two pairs of linear conductors which are perpendicular to each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.