Metal detection methods and apparatus wherein a numeric representation of the sense signal and a noise contribution to the sense signal are produced
US7391217B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2006 |
| Grant date | Jun 24, 2008 |
| Priority date | — |
| Expiry date | Feb 6, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/101
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Metal detectors include a sense coil coupled to an analog to digital converter that produces a numeric representation of an electrical signal associated with a conductive object situated in an active region of a sense coil. The numeric representation is processed to obtain a noise contribution associated with random noise, fixed pattern noise, and/or thermal drift. The noise is subtracted from the numeric representation to produce a numeric difference. The numeric difference includes contributions associated with conductive objects located in a sense volume defined by the sense coil. The numeric difference (or the numeric representation) can be digitally processed with, for example, a matched filter to enhance the conductive object contribution. The matched filter can be based on a measured sense coil speed or can be based on typical sense coil speeds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.