Method and system for determining the depth of an electrically conductive body in a medium having a known conductivity and a known permeability by measuring phase difference between a primary and secondary magnetic field
US5119028A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1990 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | Apr 26, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/165
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and system for determining the depth of an electrically conductive body in a medium having a known conductivity and a known permeability. The method comprises the steps of generating a primary magnetic field having a time-varying field strength, and transmitting that primary magnetic field into the medium. The primary magnetic field induces an electric current in the conductive body, and this electric current generates a secondary magnetic field that also has a time-varying field strength and that propagates outward from the conductive body and through the medium. The method of this invention further includes the steps of sensing the strength of that secondary magnetic field, comparing the primary and secondary magnetic fields to measure the phase difference therebetween, and then calculating the depth of the conductive body in the medium from the detected phase difference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.