Precision metal locating apparatus
US6541966B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 12, 2000 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Dec 12, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus for detecting a metal object comprises a transmitter for generating a pulsed or an alternating magnetic field in the vicinity of the metal object to be detected and a detector for detecting the secondary magnetic field induced in the metal object by the transmitted magnetic field. The detector measures at least three magnetic field gradient components of at least first order of the secondary magnetic field. The apparatus also comprises a processor for determining at least one of the position or the electro-magnetic cross-section or an estimate of the shape of the metal object from the measured magnetic field spatial gradient components. The processor fits the measured components to dipole, multiple dipole, multipole, or extended source models. In a preferred embodiment, the invention may comprise three or more pairs of gradiometric coils, or other sensing means. The detector measures at least five magnetic field gradient components of at least first order, and one or more components of the secondary magnetic field. The detector may be coils, or any other magnetic sensors. The processor enters pre-determined criteria to discriminate against detection of metal objects of no…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.