ISO INTERNATIONAL STANDARD 9555-1 First edition 1994-08-15 Measurement of liquid flow in open channels Tracer dilution methods for the measurement of steady flow - Part 1: General Mesure de debit des liquides dans les canaux decouverts -- Methodes de dilution en régime permanent utilisant des traceurs Partie1:Généralités ISO Referencenumber ISO 9555-1:1994(E) Copyright International Organization for Standardization tworking permitted without license from IHS Not for Resale ISO 9555-1:1994(E) Contents Page Scope 2 Normative reference 3 Definitions 4. Symbols and units 4.1 Symbols 2 4.2 Subscripts 3 4.3 Units of measurement 3 5 Principles of the different dilution methods 3 5.1 Constant rate injection method 3 5.2 Sudden injection method 4 6 Characteristics common to both methods 4 6.1 General formula for the calculation of discharge 4 6.2 Separate determination of tracer concentrations in the channel and in the injection solution 6.3 Direct determination of the dilution factor 5 6.4 Influence of background Clarification 7 6.5 Accuracy and limitations of the dilution method 8 Choice of tracer 6 7.1 Characteristics required of a measuring tracer 9 7.2Criteria for comparison 9 8 Choice of measuring reach 10 8.1 General considerations on the choice of a site 10 8.2 Preliminary tests and calculations 11 9 Procedure for the constant rate injection method 17 9.1 Preparation of the injection solution 17 ISO1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced microfilm, without permission in writing from the publisher. International OrganizationforStandardization Case Postale 56 . CH-1211 Geneve 20· Switzerland Printed in Switzerland ii yright International Organization for Standardizatior from IHS Not for Resale ISO ISO 9555-1:1994(E) 9.2 Injection of the solution 17 9.3 Measurement of injection rate 17 9.4Sampling 21 10 Procedure for the sudden injection method 21 10.1 Preparation of the injection solution 21 10.2 Determination of the injected volume 21 10.3 Injection of the solution 10.4 Sampling 22 11 Comparison between the two dilution methods 28 11.1 General 28 11.2 Injection of tracer 28 11.3 Sampling and analysis of results 28 12 Estimation of uncertainties 28 12.1 General 28 12.2 Uncertainties due to different kinds of error 29 12.3Sources of systematic error 29 12.4Estimation of systematic uncertainty 30 12.5 Computation of random uncertainties 30 12.6Computation of the total uncertainty 32 12.7 Working examples of computation of uncertainties 32 Annexes A Standard dilutions using pipettes and flasks 38 B Standard dilution ranges obtained with a micrometer-type microburette 40 C Analysis for variance as a test of non-randomness 42 D Bibliography 44 Copyright International Organization for Standardization Not for Re