We investigated spatial pulsations in a cylindrical arc plasma column in the electric current range I = 100-200 A and gas flow rate G = 4-8 g s-1. The distribution functions of these pulsations were obtained. On the basis of experimental results we proposed a model for the description of the pulsations. In this model, the axis of the arc O' participates at the same time on two movements: random pulsation and rotation of the column axis. The lateral and radial intensities and radial temperatures were calculated for different rotation radii and standard deviations. For this study, the spectral line of Ar I 415.8 nm was chosen. Experimental and theoretical results are in good agreement.