Measurement uncertainty assessment of Coordinate Measuring Machines by simulation and planned experimentation

Current standard procedures for the evaluation of measurement uncertainty of Coordinate Measuring Machines (CMM) being not fully satisfactory, other methods are considered. Conformity to geometric and dimensional tolerances, specified for an industrial workpiece previously involved in a comprehensive round robin test, was checked with CMM. Measurement uncertainty was also assessed exploiting a simulation method, developed at Politecnico di Torino, offering several advantages in terms of CMM operability and substantial cost savings. Estimates of measurement variability due to single and combined effects of factors considered, obtained from testing in a representative verification, are discussed in the light of results of simulation.