Thermal diffusivity measurements of particulates using the differentiated line source

A method is described in which thermal diffusivity measurements can be made on particulate materials using the identical instrumentation as described in previous papers for measuring thermal conductivity. The measurements for the two properties can be made simultaneously, thus eliminating the changes in conditions when they are made separately. This system has particular application for studies of simulated lunar, planetary, or asteroidal surfaces in which laboratory measurements can be correlated with astronomical observations of thermal inertia. A representative set of data is shown which gives thermal diffusivity and thermal conductivity measurements on a particulate basalt in which the values for each temperature were taken simultaneously. A value for specific heat is calculated for measurements taken at each temperature.