Patent ID: 6813513
Filing Date: 2004-11-02
Classification: G01R

Abstract:
A method of measuring magnetic fields, comprising the steps of:arranging a magnetically resonant sample at a measuring point on a surface of an imaginary sphere in a measuring space; applying intermittently a gradient magnetic field while a gradient is successively varied from a maximum gradient in one polarity to a maximum gradient in a reverse polarity and then said gradient is successively varied from a maximum gradient in said reverse polarity to a maximum in said first polarity; carrying out RF excitation during intermittence of said gradient magnetic field to measure FID signals generated by said sample; calculating differentials of phases of said FID signals; calculating a magnetic field intensity at said measuring point on basis of hysteresis of differences in said differentials accompanying completion of said round of gradients; and fitting said magnetic field intensity into a spherical surface function representing a magnetic field intensity distribution in said measuring space.