Modelled temperature at the disk surface as a function of the position of the H/H₂ transition for various radiation fields and adopting the geometries of 105-600 as a large proplyd and HST10 as a small proplyd. The points are the positions where the models are calculated and corresponding solid lines are cubic interpolations. The dotted vertical line corresponds to P_trans = 1. On the left side of this line, the H/H₂ transition is inside the disk, while on the right side of this line the H/H₂ transition is inside the envelope.