Observed Stokes I and V profiles (solid lines) and temporally averaged profiles (dotted lines) at the MBP in PMJ 1 during three different temporal stages. The labels on each panel indicate the B_LOS, γ and B values inferred from Eqs. (5) and (6), evaluated in the line wings (magenta) and the line core (green). The profiles resulting from the WFA fits are shown with magenta and green markers for the wings and the line core, respectively.