Estimation of the contact area of solids by electrothermal analogy

A method of thermal measurements has been proposed for determining the real surface contact area. Measurement of the true contact area is somewhat difficult. We propose here a method of contact area measurement, which is, in essence, an idealization of the well-known probe method employed in surface studies. In this study, to determine (estimate!) the fraction of the contact surface area projected onto the plane of a geometrical area of the section of the surface, it is proposed to use the electrothermal analogy. Considered in terms of this analogy, electrical conductance is assumed to correlate with heat transfer. As a result, the real contact area is found to be millions of times smaller than the area of the plane surface.