METHOD FOR INDUCTION FREQUENCY SOUNDING Russian patent published in 2000 - IPC

FIELD: geophysics. SUBSTANCE: method involves generation of alternating magnetic field with different frequencies in sequence. At each frequency, method involves measurement of real and imaginary constituents of secondary magnetic field by means of two receiving detectors, which are located along same line with generation circuit. Direct field signal is compensated by means of two opposite-connection detectors under condition that ratio of magnetic moment of first detector at mean frequency of band to cubic distance from center of first detector to center of generation circuit is equal to ratio of same values for second detector. Moments of receiving detectors are stabilized in working bandwidth by means of condition that wall thickness of cylindrical ferrite core of each detector is equal to one third of skin layer of electromagnetic field in core material. EFFECT: possibility of rigid fixation of position of detectors with respect to generation circuit. 2 cl, 1 dwg