The methodology disclosed permits the testing of fluids, solids, powders and pastes through the measurements of effusivity. Effusivity is a measurement that combines thermal conductivity, density, and heat capacity. Blend uniformity, homogeneity, miscibility, concentration, voidingdelamination, and moisture content are exemplary of the applications to which the present methodology is applicable. The method of monitoring homogeneity, miscibility, concentration, voidingdelamination, and moisture content in a material comprises the steps of measuring effusivity of a first portion of the material, measuring effusivity of a second portion of the_material, comparing each measurement. The caparison may be between the measurements themselves or to a predetermined range of values and indicating which portion has an out of range measurement. The method of monitoring blend uniformity in a mixture containing a plurality of components to be mixed, comprises the steps of providing a first composition and a second composition, each having a different effusivity, mixing said first composition and said second composition, measuring effusivity in said mixture during mixing, determining the relative standard between measurements, and correlating the relative deviation for a determination of blend uniformity.