ISO INTERNATIONAL STANDARD 9827 First edition 1994-06-15 Measurement of liquid flow in open channels by weirs and flumes Streamlined triangular profile weirs Mesure de débit des liquides dans les canaux découverts au moyen de déversoirs et de canaux jaugeurs Déversoirs carénés a seuit a profil triangulaire ISO Reference number ISO9827:1994(E) No reproduction or networking permitted withou Not for Resale ISO 9827:1994(E) Contents Page 1 Scope 2 Normative references 3 Definitions 4 Units of measurement 5 General requirements 5.1 Site selection 5.2 Installation conditions 6 Maintenance 3 7 Measurement of head 3 7.1 General 3 7.2 Stilling or float well 3 7.3 Zero setting 3 Streamlined triangular profile weirs 8.1 Specification for a standard weir 8.2 Location of head measurement section 8.3 Location of tail water level measurement section 4 8.4 Conditions for modular flow 6 Discharge calculation 9.1 Discharge equation 9.2 Coefficients 6 9.3 Limitations 11 9.4 Uncertainty of measurement 11 10 Uncertainties in flow measurement 11 10.1 General 11 10.2 Sources of error 11 0 1SO 1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by anymeans,electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. InternationatOrganizationforStandardization CasePostale56.CH-1211Geneve20Switzerland Printed in Switzerland i No reproduction or networking permited without license from IHS Not for Resale ISO 9827:1994(E) 0 ISO 10.3 Kinds of error 12 10.4 Uncertainties in values of coefficients C and Cdr 12 10.5 Uncertainties in measurements made by the user 12 10.6 Combination of uncertainties 13 10.7 Presentationof results 13 11 Example 13 ili Copyright Intermational Organization for Standardization No reproduction or networking permitted without license from IHS Not for Resale