Measurements of the thermal conductivity of gases and gas mixtures,methods and results

Two methods for measuring the thermal conductivity have been employed:

1. a cylindrical cell type of apparatus for absolute measurements, with an accuracy of 0.5%.
2. a thermistor katharometer bridge for differential measurements, allowing an accuracy of 0.1%. The thermistor bridge is described in some detail and its performance is analysed.

Results are presented for a number of pure gases and binary mixtures. A special study was made of mixtures with water vapour or heavy water vapour as a component. Measurements were performed at room temperature and 333 K. In general our results compare well with those of other investigators, although differences are noted that surpass the degree of accuracy we believe to hold for our values. For a number of the binary mixtures investigated no results have -to our knowledge-been reported previously. The results for six of the binary mixtures containing water as a component are represented by a Wassiljewa-type formula. No agreement was obtained with values calculated from four different theories based on this formula.