Thermal diffusion in the gas mixture CH4–Ar

The temperature dependence of the thermal diffusion factor αT for the CH4–Ar system has been studied by a two-bulb method in the temperature range 300–1100 °K. The plots of αT vs the temperature show a normal behavior with a gradual increase of αT with temperature. The composition dependence of αT has also been studied for this system, the measurements covering the composition range 10%–90%CH4. The αT vs composition of CH4 curves show a minimum at all temperatures, which are more clearly defined at high temperatures. Analysis of the gas mixtures was carried out by means of the well-known Katharometer technique.