Locating an inaccessible object by detecting horizontal and vertical components of a magnetic field
US6107801A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1998 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Oct 8, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/081
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
If a solenoid is mounted on an underground object, such as a boring tool, magnetic fields generated by an electric current flowing through that solenoid can be detected by a suitable detector at or above the surface. If the axis of the solenoid is tilted, the maximum value of the field is not directly above the solenoid. Therefore, the present invention makes use of measured values of horizontal and vertical components of the magnetic field to determine the separation of the detector and the solenoid, and also, by making use of a tilt sensor associated with the solenoid to derive a prediction of the ratio of the horizontal and vertical components of the field at a position vertically above or below the solenoid. If that predicted value of the ratio is then compared with the measured value of the ratio, the two will coincide when the detector is vertically above the solenoid. Thus, by moving the detector until such coincidence is obtained, the position of the solenoid can be determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.