Evaluation of Uncertainty in Angle Measurement performed on a Coordinate Measuring Machine

Coordinate Measuring Machine (CMM) is a universally accepted instrument that is widely used for inspection in industries and laboratories. Evaluation of uncertainty in dimensional measurement is very important for any measurement process. The components and the parts of the mechanical systems must have the accurate dimensions to meet the functional requirements. The environmental conditions and measurement methodhighly influence the accuracy of measurement process.This paper focuses on estimating the uncertaintyin angle measurementscarried out using CMM. In this study, anglegauge blocks are used as the reference materials for assessing the uncertainty in measurement using a CMM. An uncertainty estimation is carried out according to the guide to the expression of uncertainty in measurement (GUM). The influence of position accuracy, environment temperature, vibration, measurement and probing strategies are analysed and uncertainty in angle measurement is estimated as 40 arc seconds.