TSO NTERNATIONAL STANDARD 2975/VI INTERNATIONAL ORGANIZATION FOR STANDARDIZATION -MEK.IVHAPOJIHA OPTAHM3ALIMS IO CTAHJIAPTW3ALMM.ORGANISATION INTERNATIONALE DE NORMALISATION Measurement of waterflowinclosed conduits- Tracer methods Part VI : Transit time method using non-radioactive tracers Mesure de debit de I'eau dans les conduites fermees -Methodes par traceurs PartieVI:Methodedutempsdetransitutilisantdestraceursnonradioactifs First edition-1977-02-15 ISO 2975/VI-1977 (E) UDC532.574.87 Ref.No. ISO 2975/V1-1977 (E) Descriptors : flow measurement, water flow, pipe fiow, tracer methods. Price based on 13 pages 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 up 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. Draft International 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/VIwas drawn up by Technical Committee ISO/TC 30, Measurement of fluid flow in closed conduits, and was circulated to the member bodies in January 1976. It has been approved by the member bodies of the following countries : Australia Germany Romania Belgium India Turkey Chile Italy United Kingdom Finland Mexico Yugoslavia France Netherlands No member body expressed disapproval of the document. International Organization for Standardization,1977 Printed in Switzerland ISO2975/VI-1977(E) INTERNATIONALSTANDARD Measurement of water flow in closed conduits Tracer methods Part Vl : Transit time method using non-radioactive tracers INTRODUCTION where 0 This International Standard is the sixth of a series of V is the volume of the conduit between the detector standards covering tracer methods of water flow measure- positions; ment in closed conduits. is the transit time of the labelled fluid particles. The complete series of standards will be as follows : In general, the theoretical condition for the validity of the Part I : General. formula is that the measuring section be"closed to - diffusion" : i.e. that the ratio of the local velocity to the Part Il : Constant rate injection method using non- longitudinal dispersion coefficient be equal at both ends of radioactive tracers. the measuring section. Part Ill : Constant rate injection method using radio- - In practice this condition is fulfilled when the conduit has active tracers. a constant cross-section. - Part IV : Integration (sudden injection) method The value of f is obtained by measuring the difference in using non-radioactive tracers. abscissae of characteristic points (in theory : centre of gravity, but in practice other characteristic points may be Part V : Integration (sudden injcction) method using found, see 5.6) of recorded distributions, corresponding to radioactive tracers. concentration/time distributions or their integrals, obtained Part VI : Transit time method using non-radioactive at each detection cross-section. The signal from the detec- tracers. tors shall be proportional to the tracer concentration. The value of the proportionality coefficient and hence the Part Vll : Transit time method using radioactive absolute concentration value need not, however,be known tracers. exactly. SCOPEAND FIELDOF APPLICATION 1 3 REQUIREDCONDITIONS This International Standard specifies the transit time 3.1 Tracer method using non-radioactive tracers for the measurement of water flow rate in closed conduits. The tracer shall meet the general requirements defined in clause 5 of part 1. 2 PRINCIPLE Sodium chloride is commonly used as the tracer, mainly because of the linear