EN ISO 748:2021
(Main)Hydrometry - Measurement of liquid flow in open channels - Velocity area methods using point velocity measurements (ISO 748:2021)
Hydrometry - Measurement of liquid flow in open channels - Velocity area methods using point velocity measurements (ISO 748:2021)
This document specifies methods for determining the velocity and cross-sectional area of water flowing in open channels and for calculating the discharge employing point velocity measurement devices.
It is applicable to methods using rotating-element current meters, acoustic doppler velocimeters (ADVs), acoustic doppler current profiler (ADCP) stationary method, surface velocity measurement including floats and other surface velocity systems.
Although some general procedures are discussed, this document does not describe in detail how to use or deploy these systems.
NOTE For detailed procedures, refer to guidelines from instrument manufacturers and the appropriate public agencies.
Hydrometrie - Durchflussmessung in offenen Gerinnen mittels Fließgeschwindigkeitsmessgeräten (ISO 748:2021)
Dieses Dokument legt Verfahren zur Bestimmung von Geschwindigkeit und Querschnittsfläche von Wasser, das durch offene Gerinne fließt, und für die Berechnung des Durchflusses unter Einsatz von Geräten zur punktuellen Geschwindigkeitsmessung fest.
Es ist anwendbar auf Verfahren unter Anwendung von Strömungsmessgeräten mit rotierenden Elementen, akustischen Doppler-Strömungsmessgeräten (ADV, en: Acoustic Doppler Velocimeter), akustischen Doppler-Geräten zum Messen von Geschwindigkeitsprofilen (ADCP, en: Acoustic Doppler Current Profiler) im stationären Verfahren, Messung der Oberflächengeschwindigkeit unter Einbeziehung von Schwimmern und anderen Systemen zur Bestimmung der Oberflächengeschwindigkeit.
Obwohl einige allgemeine Verfahren erörtert werden, wird in diesem Dokument nicht im Einzelnen beschrieben, wie diese Systeme anzuwenden oder einzusetzen sind.
ANMERKUNG Hinsichtlich detaillierter Verfahren wird auf Leitlinien von Geräteherstellern und entsprechenden Behörden Bezug genommen.
Hydrométrie - Mesurage du débit des écoulements à surface libre - Méthodes d'exploration du champ des vitesses utilisant le mesurage de la vitesse par point (ISO 748:2021)
Le présent document spécifie des méthodes permettant de déterminer la vitesse et l’aire de la section transversale d’un écoulement d’eau à surface libre et de calculer le débit à l’aide de dispositifs de mesurage de la vitesse par point.
Il est applicable aux méthodes utilisant les courantomètres à élément rotatif, les vélocimètres à effet Doppler acoustique (ADV), à la méthode stationnaire avec profileur acoustique de vitesse à effet Doppler (ADCP), et aux mesurages de la vitesse superficielle, y compris les flotteurs et autres systèmes de vitesse superficielle.
Bien que certaines procédures générales soient abordées, le présent document ne décrit pas en détail comment utiliser ou déployer ces systèmes.
NOTE Pour les procédures détaillées, se référer aux lignes directrices des fabricants d’instruments et des organismes publics appropriés.
Hidrometrija - Merjenje pretoka tekočin v odprtih kanalih - Metode za določanje območja hitrosti z uporabo točkovnih meritev hitrosti (ISO 748:2021)
Ta dokument določa metode za določanje hitrosti in prečnega prereza območja vode, ki teče v odprtih kanalih, ter za izračun izpusta z uporabo naprav za točkovno merjenje hitrosti. Uporablja se za metode, pri katerih se uporabljajo merilniki pretoka z vrtljivim elementom, akustični Dopplerjevi merilniki hitrosti (ADV), stacionarna metoda akustičnega Dopplerjevega merilnika pretoka (ADCP), merjenje površinske hitrosti, vključno s plovci in drugimi sistemi površinske hitrosti. Obravnavani so nekateri splošni postopki, vendar ta dokument ne zagotavlja podrobnega opisa, kako uporabljati ali uvajati te sisteme. OPOMBA: Za podroben opis postopkov glej smernice proizvajalcev instrumentov in ustreznih javnih agencij.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-februar-2022
Nadomešča:
SIST EN ISO 748:2008
Hidrometrija - Merjenje pretoka tekočin v odprtih kanalih - Metode za določanje
območja hitrosti z uporabo točkovnih meritev hitrosti (ISO 748:2021)
Hydrometry - Measurement of liquid flow in open channels - Velocity area methods using
point velocity measurements (ISO 748:2021)
Hydrometrie - Durchflussmessung in offenen Gerinnen mittels
Fließgeschwindigkeitsmessgeräten (ISO 748:2021)
Hydrométrie - Mesurage du débit des écoulements à surface libre - Méthodes
d'exploration du champ des vitesses utilisant le mesurage de la vitesse par point (ISO
748:2021)
Ta slovenski standard je istoveten z: EN ISO 748:2021
ICS:
17.120.20 Pretok v odprtih kanalih Flow in open channels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 748
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2021
EUROPÄISCHE NORM
ICS 17.120.20 Supersedes EN ISO 748:2007
English Version
Hydrometry - Measurement of liquid flow in open
channels - Velocity area methods using point velocity
measurements (ISO 748:2021)
Hydrométrie - Mesurage du débit des écoulements à Hydrometrie - Durchflussmessung in offenen Gerinnen
surface libre - Méthodes d'exploration du champ des mittels Fließgeschwindigkeitsmessgeräten (ISO
vitesses utilisant le mesurage de la vitesse par point 748:2021)
(ISO 748:2021)
This European Standard was approved by CEN on 24 October 2021.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 748:2021 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 748:2021) has been prepared by Technical Committee ISO/TC 113
"Hydrometry" in collaboration with Technical Committee CEN/TC 318 “Hydrometry” the secretariat of
which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2022, and conflicting national standards shall be
withdrawn at the latest by June 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 748:2007.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 748:2021 has been approved by CEN as EN ISO 748:2021 without any modification.
INTERNATIONAL ISO
STANDARD 748
Fifth edition
2021-11
Hydrometry — Measurement of liquid
flow in open channels — Velocity
area methods using point velocity
measurements
Hydrométrie — Mesurage du débit des écoulements à surface libre —
Méthodes d'exploration du champ des vitesses utilisant le mesurage
de la vitesse par point
Reference number
ISO 748:2021(E)
ISO 748:2021(E)
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
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Published in Switzerland
ii
ISO 748:2021(E)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle of the methods of measurements . 1
5 Site selection .2
5.1 Selection of site . 2
5.2 Demarcation of site. 3
6 Measurement of cross-sectional area . 3
6.1 General . 3
6.2 Measurement of width . . 3
6.3 Measurement of depth . 3
7 Measurement of mean velocity . 4
7.1 Determination of mean velocity using point velocity measurements . 4
7.1.1 General . 4
7.1.2 Measurement procedure . 4
7.1.3 Oblique flow . 5
7.1.4 Determination of the mean velocity in a vertical . 5
7.1.5 Integration method . 8
7.1.6 Errors and limitations . 8
7.2 Determination of mean velocity from surface velocity . 8
7.2.1 General . 8
7.2.2 Non-contact systems . 9
7.2.3 Surface one-point method by current meter . 9
7.2.4 Measurement of velocity using floats . 9
7.2.5 Exceptions . 9
7.2.6 Main sources of error . 9
8 Computation of discharge .10
8.1 Arithmetic methods . 10
8.1.1 General . 10
8.1.2 Mean-section method. 10
8.1.3 Mid-section method . 10
8.1.4 Bathymetric verticals . 11
8.2 Independent vertical method . 11
8.3 Mean-section method — Horizontal planes . 13
9 Uncertainties in flow measurement .13
9.1 General .13
9.2 Method of calculating the uncertainty in discharge by measurement of velocity by
current meter . . 14
9.2.1 General . 14
9.2.2 Contributory uncertainties . 14
9.3 Method of calculating the uncertainty in discharge by measurement of velocity
using floats . 16
9.3.1 General . 16
9.3.2 Contributory uncertainties . 16
9.3.3 Combined uncertainty in discharge . 17
9.4 Limitations .
...
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