Community Research and Development Information Service - CORDIS


An intercomparison of high accuracy roundness measurements has been made on behalf of the Commission of the European Communities under its Programme for Applied Metrology and Chemical Analysis (Community Bureau of Reference, BCR).
In a previous intercomparison of roundness standard calibrations (BCR project MTR 123) the agreement among the National Metrology Institues was not fully satisfactory. Since then, a number of laboratories have improved their equipment. For these reasons, it was decided to make a new intercomparison focused on the highest level of accuracy.
In this new intercomparison, measurements of the deviation from roundness of selected profiles on three artifacts were performed by seven National Metrology Institutes and one accredited laboratory. The standards circulated in this exercise, which took place in 1993 to 1994, were a hemisphere and two complete spheres.
The overall results have shown a very satisfying agreement. Technical improvements can be made in some laboratories and, in general, on the uncertainty evalatuion. This intercomparison may help the laboratories to solve some residual or marginal problems as well as to better understand the uncertainty components. Also the stability of the circulated standards was confirmed within 10 nm.
The frequency responses of the instruments seem to be different. It was not the purpose of this project to determine their frequency response, but the results show a tendency towards larger discrepancies when higher frequencies are included in the measurements. ts.

Additional information

Authors: FRENNBERG M, Sveriges Provnings-och Forskningsinstitut, Borås (SE);SACCONI A, Istituto di Metrologia G Colonnetti, Torino (IT)
Bibliographic Reference: EUR 16217 EN (1996) 41pp., FS
Availability: Available from the SMT Programme Office, European Commission, DG XII-C-5, 200 rue de la Loi, B-1049 Bruxelles (BE)
ISBN: ISBN 92-827-7783-9
Record Number: 199611196 / Last updated on: 1996-11-11
Original language: en
Available languages: en