ISO INTERNATIONAL STANDARD 11631 First edition 1998-11-01 Measurement of fluid flow Methods of specifying flowmeter performance Mesure de débit des fluides Méthodes de spécification des performances des débitmetres ISO Reference number ISO 11631:1998(E) by IHS under lic itted without license from IHS Not for Resale ISO 11631:1998(E) Contents 1 Scope 2 Normative reference.. 3 Terms and definitions 4 General requirements 5Traceability 6 Uncertainty of flow measurement 7 Conditions of use .8 8 Traceability group... Annex A (informative) Illustrations of linearity. 11 Annex B (normative) Repeatability. ..13 Bibliography ... @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. InternationalOrganizationforStandardization Case postale 56 . CH-1211 Geneve 20 · Switzerland Internet [email protected] Printed in Switzerland Not for Resale @ ISO ISO 11631:1998(E) Foreword ISO (the International Organization for Standardization) is a worldwide federationofnationalstandardsbodies(lSOmemberbodies).Theworkof preparing International Standards is normally carried out through isO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non- governmental, in liaison with isO, also take part in the work. isO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International a vote. International Standard ISO 11631 was prepared by Technical Committee TC 30, Measurement of fluid flow in closed conduits, Subcommittee SC 9, General topics. Annex B forms a normative part of this International Standard. Annex A is for information only ili Copyright International Organization for Standardization Not for Resale