Journal of the Optical Society of America · 1959 · 25 citations · 4 references
EngineeringEarth SciencesFormation EvaluationMetrologySpatial StatisticsGrain Size DistributionGrain-size AnalysisSurface MetrologySurface RoughnessSurface Roughness EffectsSurface TopographyAperture Geometry EffectsAperture MeasurementDensityExperimental Study DesignGranularityGranulometrySurface Roughness Measurement
Experimental data on the constancy of Selwyn granularity, S=σ(D)·(2a)12, with variations in scanning-aperture diameter are presented. Selwyn granularity S is found to be essentially constant for a series of aperture diameters from 7.5 to 384 μ if the sample is clean and has no macroscopic variations in density. The effect of sample imperfections, such as density wedging, streaks, scratches, and dirt is discussed.
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