Continuous-depth-indicating underground pipe and cable locator
US6140819A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 1998 |
| Grant date | Oct 31, 2000 |
| Priority date | — |
| Expiry date | May 26, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/15
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An underground pipe and cable locator for continuous depth readings comprises a top and bottom receiver antenna sensor each connected to respective amplifier channels. A separate transmitter is used to stimulate electromagnetic radiations from a buried pipe, cable, or other electrical conductor. The bottom receiver antenna sensor is sampled and used to synchronize a phase locked loop controlled oscillator. The exceedingly faint and noise-riddled signals obtained from the top and bottom receiver antenna sensors are full-wave rectified without the use of rectifiers or diodes that can introduce distortions and offsets. Such signals are full-wave rectified by synchronously switching between inverted and non-inverted copies with an analog switch such that only the positive cycles of each are output in one pulse train. A continuous output is therefore obtainable from the top and bottom receiver antenna sensors, and this, in turn, permits a continuous display of the depth estimate of the buried conductor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.