0 (ISO)2 2975/1 NTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOIHA OPIAHH3ALIHH HO CTAHIAPTH3ALIHH.ORGANISATION INTERNATIONALE DE NORMALISATION Measurement of water flow in closed conduits - Tracer methods - Part I : General Mesure de debit de I'eau dans les conduites fermees -- Methodes par traceurs -- Partie/:Généralites First edition - 1974-05-01 Ref. No. ISO 2975/1-1974 (E) UDC 681.121.84 Descriptors : liquid flow, water flow, pipe flow, flow measurement, isotopic labelling. Price based on 11 pages Not for Resale FOREWORD ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (IsO Member Bodies). The work of developing International Standards is carried out through ISO Technical Committees. Every Member Body interested in a subject for which a Technical Committee has been set governmental and non-governmental, in liaison with IsO, also take part in the work. Draft tnternational Standards adopted by the Technical Committees are circulated to the Member Bodies for approval before their acceptance as International Standards by the ISO Council. International Standard ISO 2975/l was drawn up by Technical Committee ISO/TC 30, Measurement of fluid flow in closed conduits, and circulated to the Member Bodies in October 1972. It has been approved by the Member Bodies of the following countries : Australia Thailand Japan Belgium Netherlands United Kingdom Czechoslovakia New Zealand U.S.A. France U.S.S.R. South Africa, Rep. of Germany Spain Hungary Switzerland No Member Body expressed disapproval of the document. @ International Organization for Standardization, 1974 : Printed in Switzerland ii without license from IHS Not for Resale CONTENTS Page 0 Introduction 1 1 Scope and field of application 1 2 Vocabulary and symbols 1 3 Units 1 4 Choice of method 1 4.1 Comparison between dilution methods and methods based on transit time measurement 1 4.2 Comparison between the two ditution methods (constant rate injection and integration (sudden injection) procedure) 2 5 Choice of tracer 5.1 General 2 5.2 Advantages or disadvantages of the different tracers 3 6 Choice of measuring length and adequate mixing distance 4 6.1 Introduction 4 6.2 Mixing distance 4 6.3 Examples of methods of reducing mixing distance 5 6.4 Multi-orifice sampling 5 6.5 Choice of measuring length 5 7 Errors 6 7.1 General 6 7.2 Systematic errors 6 7.3 Random errors 6 Annex 8 ili Copyright International Organization for Standardization Not for Resale