The net volumetric emission coefficient was calculated using the escape factor method for Ar/Fe and Ar/H-2/Fe plasmas, at atmospheric pressure, over the temperature range from 3000 K to 30,000 K The calculation involved 712 lines for Ar I, Ar II, and Ar III, 3481 lines for Fe I, Fe II, and Fe III, and 230 lines for H in the Ar/H-2/Fe case. A semiempirical method was used for the determination of line profiles and line broadening. The results show a strong influence of the presence of even traces of iron vapors at low temperatures where the volumetric emission increases by several orders of magnitude. Special attention is given to self-absorption of the argon resonance lines which prevents the radiation from escaping within a few millimeters from the emission source.