The positive column of a glow discharge is placed along the axis of a cylindrical cavity excited in the TM010 mode. The transmission of 3 cm waves through the cavity and the shift in resonant frequency are observed as a function of discharge current. It is shown that from these measurements values of the complex conductivity of the electron gas can be calculated. Curves of the measured conductivity components as functions of pressure and current are given. From theoretical expressions for the conductivity values of electron density are calculated. Langmuir probe studies are carried out and adequate agreement is found. Finally, mean free path and mean free time between collisions are calculated from the conductivity values and hence the variation of collision cross-section with temperature is found.
