Patent ID: 9310507
Filing Date: 2016-04-12
CPC Classification: E21B,G01D,G01V

Claim Text:
1. An apparatus, comprising: a transmitter configured for rotating a magnet about an axis in a way which produces a rotating magnetic dipole field; a receiver arranged at a distance D from the transmitter at least approximately in a predetermined positional relationship with the transmitter at least approximately on said axis and configured to periodically sense a set of total flux intensities in three dimensions, of said rotating magnetic dipole field, successively through a plurality of angularly distributed rotation angles of said magnet sufficient to characterize the total flux intensity with rotation of the rotating magnetic dipole field; and a processor configured to use the set of total flux intensities in conjunction with distance D to determine a dipole strength m of the rotating magnetic dipole field and to use said set of total flux intensities with distance D to determine an average flux intensity which determines the dipole strength m of the rotating magnetic dipole field based on the expression: where B