Proximity Errors in Quasistatic Magnetic Field Measurements on Line Sources Using Coil Probes

Systematic errors occur in the measurement of quasistatic magnetic fields using coil-based sensors if the field is not spatially uniform across the area of single axis coils, or over the volume of three-axis coil probes. These effects have previously been analyzed for the dipole field distribution produced by an infinitesimally small current loop. In many practical measurement scenarios, however, the magnetic field source is often a more extended cable, or group of cables, carrying relatively low frequency currents. Thus, this paper predicts the proximity errors for magnetic field measurements using three-axis coil probes in the vicinity of a single line current and for a pair of opposing parallel line currents.