Measurements of Thermal-Conductivity Divergence in the Supercritical Region of CO2

Precise thermodynamic measurements have been made to determine the thermal conductivity of C${\mathrm{O}}_2$ near its critical density using a horizontal parallel-plate apparatus. Tests were conducted for $0.89<T-T_c<5.48\mathrm{}$ °C. The exponent for the thermal-conductivity divergence on the critical isochore was found to be 0.67 ± 0.02, in good agreement with recent predictions from theory and from light-scattering experiments.