ISO INTERNATIONAL STANDARD 3650 Second edition 1998-12-15 Geometrical Product Specifications (GPS) Length standards Gauge blocks Speécification géométrique des produits (GPS) Etalons de longueur - Cales-étalons Tso Referencenumber ISO3650:1998(E) py IHS under Not for Resale ISO 3650:1998(E) Contents 1 Scope 2 Normative references 3Definition 4 Nomenclature of faces .. 5 Basis of measurement, traceability, reference condition. 5.1 Unit of length: metre 5.2 Traceability of the length of a gauge block... 5.3 Reference temperature and standard pressure 5.4 Reference orientation of gauge blocks 6 General dimensions, material properties, marking ... 6.1 General dimensions 6.2 Material properties 6.2.1 Material 6.2.2 Coefficient of thermal expansion. 6.2.3 Hardness. 6.2.4 Dimensional stability 6.3 Marking 7 Metrological requirements. 7.1General 6 7.2 Flatness tolerance, tf 7.2.1 Gauge blocks with nominal lengths exceeding 2,5 mm .. 7.2.2 Gauge blocks with nominal lengths up to 2,5 mm 7.3 Measuring faces ISO1998 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International OrganizationforStandardization Case postale 56 . CH-1211 Geneve 20 · Switzerland Internet [email protected] Printed in Switzerland onal Organization for Standardizatior @ ISO ISO3650:1998(E) 7.4 Side faces. 7.4.1 Flatness 7.4.2 Parallelism .8 7.4.3 Perpendicularity 7.4.4Edges 8 Calibration of gauge blocks... 8.1 General 8.2 Wringing tes 10 8.3 Measurement by interferometry . .10 8.3.1 Measured length .10 8.3.2 Auxiliary plate 10 8.3.3 Corrections to measurements by interferometry . .10 8.3.4Calibrationcertificate 0 8.4 Measurement by comparison. 11 8.4.1 Principle of measurement.. 8.4.2 Central length 8.4.3 Method of determining length by comparison . 8.4.4 Variation in length 11 8.4.5 Correction: 12 8.4.6Calibrationcertificate.. .12 Annex A (informative) Example of a device for the comparison of gauge blocks 13 Annex B (informative) Relation to the GPS matrix model 4 Annex C (informative) Bibliography .. 15 Copyright International Organization for Standardization ili Not for Resale