We compare the diagonal μ and off-diagonal κ permeability tensor components of magnetized polycrystalline ferrites given by the theoretical model of Gelin and Berthou with experimental ones at microwave frequencies. We used a broad-band and noniterative measurement technique recently developed within our research group. Whatever the ferrite magnetization state is, simulated and measured μ and κ points agree well. This study provides an experimental validation of the Gelin-Berthou model. Moreover, by using this characterization method, we show how the measurement of the magnetic properties can be affected by the size of the ferrite sample under test.