Magnetic field characterization of electrical appliances as point sources through in situ measurements

It is shown that magnetic field exposure from a point source can be studied by characterizing the source with a magnetic dipole. A technique based on in situ measurements of amplitude and phase angle of three orthogonal components of the magnetic field at three points at different distances from the source was developed. The method to determine the center and the real and imaginary components of the dipole moment along the three axes is described. The characterization of the source allows the prediction of the field at any distance and along any direction from the source. The effects of background fields and of the source dimensions and complexity on the accuracy of the results are discussed.