Fixing a geographical reference of a vehicle traveling through a pipeline
US4857851A · kind A · utility
34Cited by
6References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1985 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | Jan 29, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/105
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a pipeline through which a vehicle such as a pig is travelling, a magnetically activated detector detects the presence of the approaching pig and sends a signal to switch on a transmitter unit which supplies an alternating current to an AC coil. This generates a magnetic field for a preselected period, the flux signal being then sensed by a pair of crossed coil sensors on board the pig after which the signal is processed in a unit on-board the pig. A reference pulse is then output for recording on a tape recorder also on-board the pig. This technique enables a geographical reference of the vehicle to be fixed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.