Reaffirmed 2022

NATIONAL FOREWORD

This Indian Standard (First Revision) which is identical with ISO 9824:2007 ‘Hydrometry - Measurement of free surface flow in closed conduits’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Hydrometry Sectional Committee and approval of the Water Resources Division Council.

IS 15646 was first published in 2006 in two parts. This revision is being done to amalgamate the two parts and align it with the latest version of ISO/TR 9824.

The text of ISO Standard has been considered as suitable for publication as an Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker.