Characterization of the thermal properties of gases using a thermal wave interferometer

A method suitable for the thermal characterization of gases is described. I t is based on thermal wave interference (TWI) in a cavity. A TWI device was constructed and the thermal diffusivity of different binary gas mixtures a s a function of their relative concentration was measured. From these value s, using a logarithm mixing model for the thermal conductivity of a two-pha se gas system, the thermal properties of the corresponding pure gases were calculated. The data obtained for several test gases show good agreement wi th values reported in the literature.