Optical Determination of Thermal Conductivity with a Plane Source Technique

A recently developed plane source method for non-steady-state measurements of the thermal conductivity and thermal diffusivity of transparent liquids is now being applied to the study of molten salts. In these first measurements sodium nitrate and potassium nitrate have been investigated from their melting points to about 450°C. No temperature dependence of the thermal diffusivity can be established for either of the liquids, whereas the thermal conductivity in both cases increases very slowly with the temperature. A description of the experimental arrangement is included.