• Ivana Linkeová Czech Technical University in Prague, Faculty of Mechanical Engineering, Department of Technical Mathematics, Karlovo nám. 13, 121 35 Prague, Czech Republic
  • Vít Zelený Czech Metrology Institute, Laboratories of Fundamental Metrology, V Botanice 1504/4, 150 72 Prague, Czech Republic



Hyperbolic paraboloid, tangent surface of a helix, CAD model, freeform metrology, calibration standard


An application of two ruled surfaces (i.e., surfaces generated by a motion of a straight line), a surface of hyperbolic paraboloid and a tangent surface of a cylindrical helix in freeform and gear metrology is introduced in this paper. Both surfaces have been implemented as the main functional figures in several artefacts – metrological calibration standards intended for testing the freeform capabilities of various measuring technologies (e.g., tactile point-to-point measurement and tactile scanning on coordinate measuring machine, optical scanning, computer tomography). Geometrical and mathematical properties of the surface used are summarised, CAD models of all the developed standards are presented and photos of the manufactured standards are shown.


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Refereed Articles