The effect of variability of characteristics of substances during determination of their thermophysical properties by the method of periodic heating

A nonlinear differential equation of thermal conductivity is solved using the method of periodic heating. The solution is accomplished by the method of successive approximations. Corrections to the basic equation are determined, which are associated with the effect of variability of thermal parameters for the cases of plane and cylindrical probes. The obtained results are analyzed. Examples of the calculation of the above-identified corrections are given. It is demonstrated that the values of corrections for the case of a wire probe are smaller than those for a plane probe. The thickness of the active layer for undecanol alcohol is calculated as well.