Evaluation of the uncertainty of coordinate measurements based on the formula for EL,MPE

The methodology of evaluating the uncertainty of coordinate measurements, developed at ATH (University of Bielsko-Biała) and verified within the EUCoM project, is presented, in which the only information about the accuracy of the CMM used is the formula for EL,MPE. The measurement models used for individual characteristics are derived from distance point-point, point-straight line, point-plane and straight line-straight line formulae. Information about the shape and dimensions of the measured workpiece is in the form of the minimum number of appropriately distributed points needed to define individual characteristics. The measurement model is a formula expressing the measured characteristics as a function of the differences in the coordinates of the characteristic points. The GUM uncertainty framework is used to propagate individual uncertainty components. Two models and example uncertainty budget is presented.