Estimation of Uncertainty of Coordinate Measurements According to the Type B Method

Abstract

The paper describes a new method for analytical estimation of the uncertainty component introduced by the CMM, including temperature influence. The uncertainty is estimated separately for each characteristic (dimension or geometrical deviation) given in the geometrical specification. The uncertainty is calculated directly, i.e. no analysis of the accuracy of determination of particular geometrical elements is performed. The fundamental condition enabling analytical estimation of the uncertainty is assumption that uncertainty of coordinate measurement depends on the differences of coordinates of characteristic points used to calculate particular deviation.