Excitation temperature determination of an arc formed over an ice surface using optical emission spectroscopy

Optical emission spectroscopy has been used to study an arc formed over an ice surface. DC positive voltage was applied to a flat ice surface with a 6 cm air gap to initiate electric discharge. Time-resolved spectra were recorded during the propagation of arc along the surface. Excitation temperature was measured using copper and oxygen lines and employing the relative line intensities method. Deviation from the local thermodynamic equilibrium was considered using the Burton and Blade correction factor. The investigation results showed that the excitation temperature does not vary monotonically with the discharge current.