ISO/TC 213 Working groups – Teddington/UK
„In the beginning of March I had the pleasure to attend at the NPL the meetings of the ISO/TC 213/WG 10 – Coordinate measuring machines and the ISO/TC 213/WG 4 – Uncertainty of measurement and decision rules. The meetings took place in the nice heritage-protected Bushy House in Teddington/UK.
In the meeting on computed tomography, we presented to the working group Coordinate measuring machines the progress we made at our so-called crown standard for the acceptance and reverification tests for CT systems. The basic approach of the material standard is that several rings of different diameters with a step pattern recurring at 120° (similar to a crown) can be positioned inside each other in a well-defined manner with Maxwell clamps. High-precision spheres are attached to the steps whose centre distances from each other are calibrated and serve as reference lengths for the acceptance and reverification tests of the CT systems. As the measuring range increases and the magnification of the CT decreases, more rings with larger centre-to-centre distances are added, starting from the smallest ring. The design allows the centre-to-centre distances to be calibrated with a straight vertical stylus and with maximum accuracy.
During the meeting of ISO/TC 213/WG 4 – Uncertainty of measurement and decision rules, I presented a proposal for simplified conformity and non-conformity testing based on empirical distribution functions from Monte Carlo simulations, which could supplement ISO 14253-1 in the future.“
Prof. Dr.-Ing. habil. Tino Hausotte