The Analysis of Metrological Characteristics of Different Coordinate Measuring Systems

Abstract

The aim of this paper is to examine the metrological characteristics of some of the most commonly used coordinate measurement systems in industry in a case study of the flatness error. The accuracy and measurement uncertainty of the coordinate measuring machine with contact probe, point by point mode and scanning mode, and with non - contact probe, then performance measuring arm, optical scanner and finally industrial computed tomography were analyzed. In order to exclude factors that affect the accuracy of measurement and measurement uncertainty, and are not part of the hardware structure of the CMS, the experiment was conducted on a reference workpiece and an independent software solution was used to estimate the error of flatness. The accuracy of measuring systems was determined as the difference between the reference value and the mean value of repeated measurements and the measurement uncertainty was determined according to the instructions for estimating the measurement uncertainty GUM. The results of the research showed high metrological performance of the coordinate measuring machine and the optical scanner for this measuring task. Also, it was found that industrial computed tomography gives a very large measurement error and that the measurement uncertainty is very difficult to determine.

Keywords

• accuracy
• coordinate measurement systems
• flatness error measurement uncertainty