This work deals with the diagnostics and measurements of properties of DC plasma jets working at atmospheric and lower pressures. Great efforts have been devoted to study the non-equilibrium efects generally observed at low pressure. The DC plasma torch investigated is of the type used for the deposition of different powders. DC plasma jets are characterized by their relatively high electron density and very high specific energy (of the order of 1022 m-3, and 108 J/kg respectively). Owing to their ability to heat, melt, and, in some cases, vaporize the material under treatment, DC plasma jets...