Patent · US Expired

Method and apparatus for determining the presence of or absence of an underground body

US4085360A · kind A · utility

15Cited by
10References
13Claims
0Family size

Inventor

Key dates

Filing dateJun 14, 1976
Grant dateApr 18, 1978
Priority date—
Expiry dateJun 14, 1996

Classification

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

Abstract

An instrument for detecting the presence or absence of a buried pipe or cable employs three or more generally vertical coil aerials which define a triangular or polygonal area on the ground. The natural or induced electromagnetic radiation from any underground pipe or cable cutting that area gives rise to phase differences at the aerials which can be discriminated. The aerial array may be adjustable, and the discrimination may be direct or involve mixing the received signals. Facility for listening to various frequencies, perhaps simultaneously, can be provided.

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