Patent · US Expired

Method and apparatus for locating buried conductors in the presence of plural conductors

US5754049A · kind A · utility

30Cited by
1References
15Claims
0Family size

Inventor

Key dates

Filing dateOct 17, 1995
Grant dateMay 19, 1998
Priority date—
Expiry dateOct 17, 2015

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01V3/104
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Buried conductors generally carry multi-frequency AC currents and are locatable by sensing the resulting varying magnetic flux. However the presence of several buried conductors makes location of individual conductors difficult. By investigating induced signals at a multiplicity of different frequencies it is possible to identify a frequency carried exclusively by a single conductor and use it to locate that conductor. E.g. an antenna array including three vertically spaced horizontal coils (A,B,C) is located over an apparent conductor position using vertical coils (D,E). For numerous frequencies, the terms SB/(A-B), 2SC/(A-C) and 2S (B-C)/(A-B)-(B-C)! are determined (where S=coil spacing; X=signal strength of coil X). For an exclusive frequency the three values are identical and equal to the depth of the conductor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.