One of the basic challenges of the manufacturing sector is to constantly increase the quality of products while simultaneously reducing production costs to a minimum. Quality control may involve inspecting, measuring and/or testing products to ensure that they meet quality standards, for example, that they keep within the desired dimensional tolerances. [1, 2]. Form deviations also need to be taken into account while assessing the accuracy of a product. The presence of form errors may lead to a variety of unfavorable conditions; they cause assembly problems or reduce the fatigue strength of other products. It is thus vital that state-of-the-art measuring instruments should be applied and that they should be accurate, efficient, easy to operate and versatile, i.e. applicable to various industrial conditions [3, 4].

One of the most universal measuring techniques in contemporary industry is a coordinate measuring technique. When measuring form deviations with the use of a coordinate measuring machines (CMM) users can apply various measurement strategies. The measurement strategy is the term relating to a scanning trajectory, i.e. the path along which the probe moves on the surface of the workpiece. Another factor that is crucial for measurements of form deviations is the number of probing points, which should be strictly defined by a user before the measurement. Contemporary coordinate measuring machines offer also high scanning speed, which denotes the speed of the probe moving on the surface of the workpiece. The scanning speed can reach even a few hundred millimeters per second. Another parameter that is vital for a correct evaluation of form errors is selection of a reference feature. The reference feature is a mathematically ideal feature calculated from the measurement data according to a preselected method (for example minimum zone or the least squares method).

Thus, it is vital to answer the question how selection of the measurement strategy and measurement parameters affects measurement results of the form errors. This problem has been studied by a number of researchers. For example, authors of work [6] deal with the problem of an influence of a number of probing points on the uncertainty of measurements of form errors with the use of CMMs.

Another problem investigated in the literature is development of new measuring strategies that would allow obtaining reliable results of form deviations by applying as low number of probing points as possible [7]. In industry the strategies are applied that assure probing the surface with uniform distribution of density of sampling points. However, research activities are conducted aiming at development of concepts of non-uniform sampling strategies. In general, the concepts that are under study can be divided into two groups. To the first group belong strategies defined on the basis of presumed model of irregularities of the surface, which was described, for example, in works [8] and [9]. The second group constitute so-called adaptive strategies that are usually based on Krige model [10].

Another area of research activities focused on the problem of measurements of form deviations are methods of calculation of reference features. Most of published papers in this field concern minimum zone reference features, as such features are usually more practical taking into account technological aspects of manufacturing than the least squares reference features. One of the methods that are applied to determine the minimum zone reference features are computational geometric techniques, which was described in work [11]. Apart from that, so-called particle swarm optimization [12] and genetic algorithms are applied to calculate parameters of minimum zone features.

The evaluation of surface irregularities can be also conducted with the use of wavelet transform and wavelet pockets [14-16]. In particular, methods based on wavelets are suitable to detect local surface defects, surface cracks, etc.

In industry, it is extremely important to minimize roundness errors of cylindrical surfaces, especially in elements that will perform a rotary or linear motion. It is obvious that form errors may cause noise and vibration of machine parts. In industrial practice, two approaches are basically used to measure roundness: the radial datum method and the V-block method [17]. As the accuracy of coordinate measuring machines is increasingly higher, they are employed also to measure form deviations, including out-of-roundness and out-of-cylindricity [18]. Today’s CMMs, designed for specialist measurement, are equipped with active or passive scanning probes. In the case of CMMs fitted with touch-trigger probes, the measurement time is too long and the selection of an optimal number of data points is difficult because the number of data points affects roundness profile results. The use of scanning probes improves the accuracy of measurement of form errors on CMMs.

An analysis of the state-of-the-art on measurements of form deviations of rotary workpieces shows that the problem of an influence of the scanning speed on measurement results has not been studied carefully so far. This is the reason why authors have conducted series of experiments aiming at establishing how the value of the scanning speed affects results of roundness measurements.