An experimental method for assessing the contribution of the production process variations to the task-specific uncertainty of coordinate measurements

The present paper deals with an important source of variation often neglected in uncertainty estimates of coordinate measurements: the between-sample variation. This source of variation becomes relevant to the measurement uncertainty when significant interactions occur between variations in the production process and specific limitations in the measurement process. This paper discusses some particular types of interaction which usually lead to between-sample variation in coordinate measurements. For analysing the statistical significance of the between-sample variation and for assessing its contribution to the measurement uncertainty, an experimental method using multiple calibrated workpieces is described. A case study involving the uncertainty estimation of a roundness measurement process using a coordinate measuring machine is presented. The results show the importance of considering the between-sample variation in uncertainty evaluations of coordinate measurements.

► The causes of the between-sample variation in coordinate measurements are discussed.
► A method for assessing the contribution of the between-sample variation is described.
► Results evidence the importance of considering the between-sample variation.