ISO 1438-1:1980/Amd 1:1998

Water flow measurement in open channels using weirs and Venturi flumes — Part 1: Thin-plate weirs — Amendment 1

Mesure de débit de l'eau dans les canaux découverts au moyen de déversoirs et de canaux Venturi — Partie 1: Déversoirs en mince paroi — Amendement 1

General Information

• Status: Withdrawn
• Publication Date: 15-Apr-1998
• Withdrawal Date: 15-Apr-1998
• ICS: 17.120.20 - Flow in open channels
• Technical Committee: ISO/TC 113/SC 2 - Flow measurement structures
• Drafting Committee: ISO/TC 113/SC 2 - Flow measurement structures
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 02-Apr-2008

Relations

• Revised: ISO 1438:2008 - Hydrometry — Open channel flow measurement using thin-plate weirs
• Effective Date: 15-Apr-2008
• Amends: ISO 1438-1:1980 - Water flow measurement in open channels using weirs and Venturi flumes — Part 1: Thin-plate weirs
• Effective Date: 06-Jun-2022
• Child: ISO 1438-1:1980 - Water flow measurement in open channels using weirs and Venturi flumes — Part 1: Thin-plate weirs
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 1438-1
First edition
1980-04-15
AMENDMENT 1
1998-04-15
Water flow measurement in open channels
using weirs and Venturi flumes —
Part 1:
Thin-plate weirs
AMENDMENT 1
Mesure de débit de l'eau dans les canaux découverts au moyen de
déversoirs et de canaux Venturi —
Partie 1: Déversoirs en mince paroi
AMENDEMENT 1
A
Reference number
ISO 1438-1:1980/Amd.1:1998(E)

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ISO 1438-1:1980/Amd.1:1998(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national standards bodies (ISO member bodies). The work of
preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which
a technical committee has been established 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. ISO
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
Amendment 1 to International Standard ISO 1438-1:1980 was prepared by
Technical Committee ISO/TC 113, Hydrometric determinations, Sub-
committee SC 2, Notches, weirs and flumes.
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
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Printed in Switzerland
ii

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©
ISO
ISO 1438-1:1980/Amd.1:1998(E)
Water flow measurement in open channels using weirs and Venturi
flumes —
Part 1:
Thin-plate weirs
AMENDMENT 1
Page iii
In Contents, change existing annex to:
“Annex A”
and add the following new annex:
“Annex B (informative): Guide to the design and installation of a flow straightener”
Page 2
In 6.3.3, add the following new paragraph between the existing second and third paragraphs.
However, if the maximum head to be measured is restricted to 2/3p for all types of weirs, flow
straighteners can be used to reduce the effective length of the approach channel to B + 3 h for
max
triangular and rectangular weirs and to B + 5 h for full-width weirs. This restriction is necessary
max
due to the distortion of the velocity distribution in the approach channel that would result from an
overflow running over the top of each baffle of the straightener, if the head on the weir was too high.
1)2)
NOTE —  For this purpose, the specification of a typical straightener calls for at least four
perforated plates, with a percentage open area of between 40 % and 60 % inclusive, separated from
each other by 0,2 m minimum. The perforations should be uniformly distributed. A guide for the
design and for the installation of the straightener, and also a typical example of perforation are given
in annex B.
At the foot of page 2, add the following footnotes:
1)
Kurokawa J. et al, “Flow measurement using full-width weir: Comparison of ISO, JIS and HIS
formulae” - Proc. 3rd triennial Int. Symp. on Fluid Control, Meas. and Visual - San Francisco. 1991
Au
...