An Artefact for Traceable Free Form Measurements on Coordinate Measuring Machines

摘要

A new concept of artefact, called the "Modular Free form Gauge" (MFG) has been developed. It is based on physical modelling of a given free form surface by a combination of items with regular geometry, well calibrated on their dimensions and form. The relative position is accounted for during the procedure; this information is used to generate a "calibrated" CAD model as reference for free form measurements. The architecture of the artefact, its collocation in the traceability chain, and the calibration procedure are described. The work has been focused on implementation of the uncertainty assessment procedure for free form measurements on turbine blades. A task-specific Modular Free form Gauge was developed for this application.