Development of virtual roughness comparators

Abstract

The surface roughness is inspected visually or by the contact profiling method. In both cases, actual roughness comparators with the preset roughness parameters (Ra) are used. The reference surface is created by various technological impacts. Technological processes are influenced by random factors; therefore, the reference surface has the deviations of the Ra parameter from the declared value. We suggest to control the roughness based on its image. In this case, the data available is not enough to determine the standard roughness parameters. We introduce the rough surface parameter ζ, which uses the standard parameters Ra and Rz. We studied five images of roughness comparators made on glass using a New View 7300 white light interferometer. We determined the nominal value of the roughness parameter ζ for each roughness comparator and for each line of the rough surface images of 5 comparators. We considered the images of the reference surfaces as an indirect measurement of microrelief heights. We generated a reference rough surface based on the image of the actual surface of the roughness comparator. We used Spearman correlation coefficient to identify the most characteristic fragments of the reference rough surface. The virtual rough surface comparator created by us allows to increase the objectivity of visual control of rough surfaces and measure the similarity of the target and the reference rough surfaces.