Magnetic signalling in pipelines

摘要

Method systems and apparatus for signalling within pipelines. The systems methods and apparatus make use of a unit locatable within a tubular piece of metallic structure for the transmission and/or reception of signals. The unit includes a magnetic material core ( 6 ) which provides a path for magnetic flux through the unit ( 4 ). A coil ( 81 ) is wound around a portion of the magnetic material core ( 6 ) to allow the detection and/or application of magnetic flux in the magnetic core ( 6 ). At each end of the core ( 6 ) there is pair of arms ( 63 ) which are arranged for location adjacent the inside surface of the tubular structure. In use magnetic signals flowing in the tubular structure pass through the core ( 6 ) and can be detected via the coil ( 81 ) in receive mode and similarly signals flowing in the coil ( 81 ) can cause magnetic flux to flow through the core ( 6 ) and into the metallic structure in transmit mode.