Cylindrical surfaces are common in industrial machining so accurate evaluation of cylindricity is a very important application in geometrical quantities metrology. New GPS standards describe four measuring strategies: a cross-section method, a generatrix method, a point method and so-called “bird-cage” method. The first three methods are relatively well developed. The last one, however, the most accurate method has not been well described mathematically. The paper presents the mathematical model of calculating the cylinder axis orientation with the “bird-cage” strategy.

Rotary elements constitute a large and important group of machine parts. They are common in various industries, for instance, automotive, steel and paper industries. This is the reason why the problem of accurate measurement of roundness deviation is one of the most important fields of the industrial application of surface metrology. According to the requirements of new Geometrical Product Specifications standards, correct determination of the roundness parameters requires the calculation of the location of the centre and the radius of the associated circle. Usually these values are calculated on the basis of the linearized model describing the value of the measured profile as a function of an angle. The paper presents an iterative algorithm allowing for the calculation of associated circle parameters by the least squares method. It also describes the results of the computer simulation for the non-linear model. The presented algorithm can also be applied in measurements of interrupted roundness profiles when the eccentricity is large in relation to the workpiece diameter.

Verification of engineering components having freeform profiles on a coordinate measuring machine (CMM) requires accurate measurement of sufficient number of sample points. While the measurement accuracy increases with increased sample size, it is often limited by cost and time considerations. Thus, for a given sample size, the locations of the measurement points are to be determined such that the actual shape may be effectively characterized. Several attempts are reported in the literature. A simple algorithm based on dominant points is proposed in this paper. Simulation studies have been carried out on a freeform profile. Comparison of the results with those obtained from uniform spacing and equiparameter sampling methods reveals that the proposed method performs effectively.

The Czech Metrological Institute in Prague started the research in the field of measurement of shapes, dimensions and position with the accuracy falling into the sub-micron field. It is being equipped with new measuring equipment and engages into international projects, such as, e. g. the project Nano CMM.
On the other hand, after the experience with high prices of measuring technical equipment, the institute comes with the idea to offer the possibility of measurement for practically everybody. The Internet virtual multi-sensor measuring machine has been developed for processing and measurement of two-dimensional pictures made by CCD camera, digital photographic apparatus, microscope or AFM and other devices. The virtual measuring machine serves also for modelling measurement, navigation of measurement and for teaching.

In coordinate metrology, the operator has a significant influence on the measurement result. Therefore an adequate qualification for the correct performance of measurement tasks is a necessary precondition for reliable measurement results. To impart the required competencies in an efficient and sustainable way, preparative and accompanying measures of qualification have to be combined into a holistic concept adapted to the operator’s needs and the requirements of industrial application. By mutual amendment of fundamental training in coordinate metrology and continuous learning via a workplace integrated assistance system, an efficient way is provided to reduce human influences on the measurement results and to increase their traceability.