ABSTRACT
Roughness is a measure of the topography of a surface, in the same way that hills and valleys are a measure of the Earth's topography. Topography can take many forms depending on the material and how the surface was made. The surfaces of most pieces of polished glass are covered with microscopic scratches that remain from the polishing process, and metal surfaces intended for mechanical or structural applications bear the marks of the tools that shaped them, such as cutting tools, grinding wheels, electrodischarge machining, sand blasting, and honing. This entry discusses various inspection and measurement techniques and presents the relevant surface statistics.
