The aim of our study is to analyse and understand the static and dynamic behavior of magnetic sheets, used in electrical engineering, when they are submined to a rotational magnetic field. Comparative study is done at first between two devices of Rotational Single Sheet Tester existing in laboratory. The magnetic characteristics are well measured by RSST 300. The deference's observed on the losses can be considered satisfying. However H measurement discrepancies can be higher than losses. After we propose a method for obtaining the reversible BOO law from dynamic tests. The method is investigated for GO FeSi and in frequency range between 10 to 400Hz, under constant circular induction. AIl the réversible characteristics are identical from lOto 200Hz. This confirms the validity of the approach. The obtained BOO characteristic is taken into account by a model based on total energy evaluation. An experimental checking of the model has been done. It permits to evaluate performers of the model and interpret the observing phenomena in order to take them into account.
