Abstract
The methods for obtaining the surface density of asperities and the real distribution of asperity heights, which differs from the distribution appearing on the surface profile curve, are considered about the isotropic and anisotropic surfaces. In the cace of the isotropic surfaces, the asperities are assumed to be spherical at least near summits. Then the surface density of asperities and the real distribution of asperity heights are obtained from the number of the peaks within a defined land length of the surface profile curve, the distribution of the peak heights appearing on it, the mean base radius of the spherical asperities, the distribution of the effective asperity heights and so on. In the case of the anisotropic surfaces, the asperities are assumed to be ellipsoidal at least near their summits. Then the method is derived with which those ellipsoidal asperities are replaced by spherical asperities which are equivalent to the original ones.
