ANALYTICAL SOLUTIONS DESCRIBING THE OPERATION OF A ROTATING MAGNETIC-FIELD TRANSDUCER

This work presents the analytical solutions describing the operation o f a rotating magnetic field transducer used in the eddy current defect oscopy for detecting the long flaws situated parallelly to the inspect ed piece generatrix. The method uses the expanding of the real transdu cer's three-phase system into an infinite sequence of axial and longit udinal currents whose intensity is given by a Fourier expansion, estim ating the electromotive voltage induced in the transducer. By solving the equation of diffusion for the three media and considering the boun dary conditions, the vector magnetic potential is determined for each medium, This work also presents the most important theoretical paramet ers of the transducer, as well as the experimental graphs obtained for concrete cases of the transducer's applications.