Form Metrology

Improving the accuracy of roundness measurement – D. G. Chetwynd and G. J. Siddall

Abstract The application of error separation techniques to roundness measuring instruments is investigatedexperimentally, using digital computers. The accuracy of such techniques is substantiated by comparativemeasurements with two independent multi-orientation systems. Results obtained with these and other systemsconfirm that the errors of conventional roundness measuring instruments can be reduced by a factor of ten or more…

Read More Improving the accuracy of roundness measurement – D. G. Chetwynd and G. J. Siddall
An investigation of reference criteria used in roundness measurement – D. G. Chetwynd et al.

Abstract The minimum zone, minimum circumscribing and maximum inscribing references (here grouped as ‘boundingreferences’) used in the measurement of roundness are investigated. Their behaviour is studied by formulating their definitions mathematically as optimization problems. The advantages of limacon references, both for accuracy under practical measurement conditions and for computational convenience, are investigated and the relationships…

Read More An investigation of reference criteria used in roundness measurement – D. G. Chetwynd et al.
Applications of linear programming to engineering metrology – D G Chetwynd

Computer-based metrology now makes use of exchange algorithms for computing best-fit geometries in which the solution is obtained bya series of iterations each involving the exchange of one previously unused data point for one of the dominant points of the previousiteration according to formal rules. While conferring large advantages in specific circumstances, their major significance…

Read More Applications of linear programming to engineering metrology – D G Chetwynd
Workshop requirements of surface measurement – R. E Reason

Summary of research.

Read More Workshop requirements of surface measurement – R. E Reason