Abstract : This work is a first step towards the understanding of involuntary couplings of wound components. More specifically, it refers to inductors entering a 10 cm edge cube and working in the 100 kHz-10 MHz frequency range. Two topics are particularly developed: mathematical tools required to evaluate, in near field approximation, magnetic coupling of close components and metrology that suits the characterization of the induction radiated by such a component. Some characterizations of industrial components are presented to illustrate the interest of this work. Magnetic induction surrounding an inductor is correctly described by giving its three components in numerous places. This présentation is difficult to illustrate and it does not allow easy comparison of fields. Owing to multipolar development, thèse data are synthesized, with a sufficient accuracy, by 15 constants al the most Usually, it is the scalar pseudo potential which is developed. Unfortunately, this potential is easy to connect neither to emitting ciments nor to induced voltages. Multipolar development of the vector potential makes it possible to achieve this goal and to prove that the 15 components of the émission of a component characterize also its suscepubility. Real spherical harmonies and vector spherical harmonies are original concepts introduced by tins work. The characterization bench moves a loop antenna according to angular coordmaîes. A computer controls thèse displacements and records data stemming from a lock-in amplifier. Outstanding care keeps noise within 30 nV that is essential to measure (iV magnitude voltages, Thanks to this bench, radiations of electrically équivalent inductors are compared, effectiveness of a component shielding is quantified and we now know that dipole momentum of a toroidal coil is not axial.