Influence of Normal Vectors on the Accuracy of Product's Geometrical Specification

Today, there is high demand of quality evaluation of products in terms of dimensional control through 3D measurement technology in automatized production environment. Each product has a geometric surface structure formed by a series of geometric elements, e.g. shape, dimensions, which together generate the actual integral surface. To determine the size of the product on 3D coordinate measuring machine, we need to associate the expected ideal geometric elements (e.g. line, cylinder) to non-ideal (integrated) real surface. The paper deals with the normal vectors, which have to be taken into account at each measured product and the creation of the measuring program, because incorrect choice of these vectors can influence the measuring process in such way, that result will not be the true value of the measurement of geometric elements.