Method and apparatus for tracing conductors using an alternating signal having two components related in frequency and phase
US5260659A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1991 |
| Grant date | Nov 9, 1993 |
| Priority date | — |
| Expiry date | Apr 1, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for tracing routes of conductors is disclosed. An alternating signal is applied to the object to be traced (12), and the field produced by this signal is detected remotely from the object. In order to distinguish between signals produced by the object being traced and those produced by nearby conductors (14) due to capacitive coupling, the alternating signal has first and second components, related in frequency and phase, and the field is detected at a plurality of positions. The phase relationship of the detected signals is investigated to determine unambiguously the position of the object concerned. In one embodiment, the second frequency component is a harmonic of the other. In another embodiment the frequency of the second component is the frequency of the first, plus or minus a sub-harmonic of the first.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.