Comparison of the Plummer parameters derived from true column density and the values estimated from the synthetic maps of model A. The rows correspond to parameters ρ_c, p, and M_line. The columns correspond to beam sizes equal to 3, 6, and 12 pixels, i.e., to the near, medium and far cloud distances. On the x-axis, we always plot the parameter values from N^True and on the y-axis the values from N^Obs derived with β = 2.0 and without observational noise (solid circles), with β = 2.0 and noise (open circles), and with β = 1.8 and noise (triangles).