ICS 17.120.20                          WRD 01

Reaffirmed 2022

1. Scope

This standard describes the methods of measurement of flow in rivers and artificial channels under steady or slowly varying conditions using flat-V weirs (see Fig. 1).

Annex A gives guidance on acceptable velocity distribution.

2. References

The following standards contain provisions which through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below :

1191 : 2015 Hydrometry - Vocabulary and Symbols (third revision)

16364 : 2015 Hydrometric uncertainty guidance (HUG)

ISO 4373 : 2002 Hydrometry - Water level measuring devices

ISO/IEC 98-3 : 2008 Guide Uncertainty measurement - Part 3 : Guide to the expression of uncertainty in measurement (GUM : 1995)

ISO/IEC 17025: 2005 General requirements for the competence oftesting and calibration laboratories

ISO 26906 : 2009 Hydrometry - Fishpasses at flow measurement Structures