Method and apparatus for the nondestructive testing of materials

Claim 1

IN A METHOD FOR INVESTIGATING THE DEGREE OF UNIFORMITY OF MATERIALS, THE STEPS OF ESTABLISHING A MAGNETIC FLUX PATH HAVING AT LEAST TWO GAPS THEREIN ACROSS WHICH ARE DEVELOPED POLARIZING MAGNETIC FIELDS, INSERTING A SAMPLE OF THE MATERIAL TO BE INVESTIGATED INTO ONE OF SAID GAPS TO ALTER THE MAGNETIC FIELD IN ACCORDANCE WITH A CHARACTERISTIC OF THE MATERIAL, DISPOSING IN A SECOND OF SAID GAPS A SUBSTANCE CONTAINING A PARAMAGNETIC FREE RADICAL, SIMULTANEOUSLY SUBJECTING SAID FREE RADICAL TO AN ALTERNATING MAGNETIC FIELD DISPOSED AT AN ANGLE TO THE POLARIZING MAGNETIC FIELD ACROSS SAID SECOND GAP, THE FREQUENCY OF SAID ALTERNATING MAGNETIC FIELD BEING ADJUSTED TO A VALUE AT WHICH MAGNETIC RESONANCE PHENOMENA WILL OCCUR WHEN THE INTENSITY OF THE POLARING MAGNETIC FIELD HAS A REFERENE VALUE, AND DETECTING A MAGNETIC RESONANCE PHENOMENON RESULTING FROM THE INTERACTION OF SAID POLARIZING AND ALTERNATING MAGNETIC FIELDS AND SAID FREE RADICAL AS INFLUENCED BY SAID MATERIAL SAMPLE.