Difference in the resulting T_eff (middle panel) and log g (bottom panel) when fixing log Q to those values needed to fit the He IIλ4686 or Hα lines, in the sample of stars labeled as Q3. Top panel: the weaker (stronger) wind is represented by a triangle with the peak up (down). Filled triangles are log Q obtained from He IIλ4686, and open triangles with Hα. Open circles are the values obtained when fitting both lines at the same time automatically. Stars are sorted by increasing minimum log Q in the horizontal axis. Standard deviation, maximum and mean of the differences also included in the middle and bottom panels.