Concealed electrical conductor detecting system
US4427942A · kind A · utility
19Cited by
4References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Apr 21, 1981 |
| Grant date | Jan 24, 1984 |
| Priority date | — |
| Expiry date | Apr 21, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An underground electromagnetic radiating source is detected by two coils (1, 2) one over the other. To avoid false readings due to air borne signals, their outputs are compared (13) and only if the lower coil output is a predetermined amount greater than that of the upper coil is an audio indicator (21) activated. Automatic gain control (9) is applied to both coil outputs, to limit the gain whenever either output threatens saturation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.