A Method for Estimating the Low Frequency Coupling Characteristics of a Ferrite-Cored Rod Antenna to a Long Conductor

Magnetic proximity detection systems (PDSs) used in underground mines occasionally generate false alarms when the miner-wearable component (MWC) is close to nearby conductors such as power cables. This is because the signals from the generators (antennas) of the PDS wirelessly couple to nearby cables, travel along these cables, and then couple back from the cable to a distant MWC to cause a false alarm. In order to manage such a false alarm, it is necessary to understand the basic near-field coupling characteristics from a generator to a long wire. Researchers from the National Institute for Occupational Safety and Health (NIOSH) have developed a method to measure such coupling characteristics for a ferrite-cored antenna to a straight wire. The method is introduced in this paper along with the test results.