Three electrode AC detection
US5773971A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 8, 1996 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Aug 8, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R29/085
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensor device and method for finding the location of a conductor such as a wire, having an alternating voltage and which is not readily visible, i.e. hidden in the wall of a structure or buried. The detector device has four plates in two balanced pairs and arranged in a quadrilateral with a central reference plate. This reference plate provides a common mode rejection of the background electric field typically present for instance on the wall, which is induced by the alternating voltage in the wire. A sharp signal peak is detectable immediately over the wire from a differential signal of a pair of the balanced plates, when the plates of the pair are located on either side of the wire. Also a determination based on the sum and difference of the signals from the two plates allows one to determine the relative phase induced in the two plates of each pair, which indicates the direction in which the sensor device should be moved in order for the plates to be immediately over the target wire.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.