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Production sequence of Si-spheres and interferometrical determination of the sphere volume

Long-term cooperation on simulation-based determination of measurement uncertainty using the Virtual Coordinate Measuring Machine


In addition to the determination of measurement uncertainties from repeated measurements or the calculation of analytical uncertainty budgets, Monte Carlo simulations provide a powerful means. In many cases, Monte Carlo simulations are the most suitable method to estimate the task-specific measurement uncertainty for complex 3D measurements.

In the 1990ies the PTB started to develop the Virtual Coordinate Measuring Machine VCMM in close collaboration with manufacturers and users of coordinate measuring machines (CMM). The VCMM was consequently extended in follow-up projects to suit the needs arising from novel measurement tasks and it was modified to accommodate the latest developments and advancements in measurement technology. Thus, a sophisticated digital-metrological twin was created that is well established for uncertainty estimation in manufacturing industry and research and that has been applied in DAkkS-accredited laboratories since 2001. The quality of the digital-metrological twin is ensured by the traceable parametrization of the models of the VCMM and the neutral implementation of the software by PTB, and therefore, independent of CMM manufacturers.

The PTB has established a long-term cooperation with CMM manufacturers and calibration laboratories accredited for the application of the VCMM to enable the constant progress of the VCMM development and to extend its use to new fields of metrological application. Frequent and repeated intercomparisons are foreseen to (re-)validate the implemented mathematical models and prove the users’ metrological capabilities at the same time. The cooperation is open to join for additional CMM manufacturers and calibration laboratories.

Figure: The virtual coordinate measurement machine VCMM is used to estimate the task-specific measurement uncertainty for complex three-dimensional parts in industry and calibration laboratories. Among others, the Multi-Feature Check measurement standard depicted is measured in frequent intercomparisons.



Physikalisch-Technische Bundesanstalt
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