ISO INTERNATIONAL STANDARD 4362 Second edition 1999-09-01 Hydrometric determinations Flow measurement in open channels using structures Trapezoidal broad-crested weirs Déterminations hydrométriques - Mesure de debit dans les canaux épais ISO Reference number ISO4362:1999(E) itted without license from IHS Not for Resale ISO 4362:1999(E) Contents 1 Scope 2 Normative reference .. 3 Terms and definitions 4 Installation General considerations . 5 Maintenance. 6 Measurement of water levels. 7 Trapezoidal broad-crested weirs in rectangular channels .. ...4 8 Trapezoidal broad-crested weirs in trapezoidal channels. .15 9 Uncertainties in flow measurement . .24 10 Example. Bibliography. 31 @ISO1999 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic International OrganizationforStandardization Casepostale56·CH-1211Geneve20·Switzerland Internet [email protected] Printed in Switzerland Copyright International Organization for Standardization Not for Resale @ISO ISO 4362:1999(E) Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(lSo committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas 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(lEC)onallmattersofelectrotechnicalstandardization International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 3 Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote International Standard ISO 4362 was prepared by Technical Committee ISO/TC 113, Hydrometric determinations, Subcommittee SC 2, Notches, weirs and flumes. This second edition cancels and replaces the first edition (iSO 4362:1992), which has been extended to include the ii