Astm D 3858 – 95 (Reapproved 2003) pdf free download

Standard Test Method for
Open-Channel Flow Measurement of Water by Velocity-Area
Method1

This standard is issued under the fixed designation D 3858; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of the last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope

1.1 This test method covers the measurement of the volume
rate of flow of water in open channels by determining the flow
velocity and cross-sectional area and computing the discharge
therefrom (Refs (1-7) ).2

1.2 The procedures described in this test method are widely
used by those responsible for the collection of streamflow data,
for example, the U.S. Geological Survey, Bureau of Reclamation, U.S. Army Corps of Engineers, U.S. Department of
Agriculture, Water Survey Canada, and many state and provincial agencies. The procedures are generally from internal
documents of the above-listed agencies, which have become
the defacto standards as used in North America.

1.3 This test method covers the use of current meters to
measure flow velocities. Discharge measurements may be
made to establish isolated single values, or may be made in sets
or in a series at various stages or water-level elevations to
establish a stage-discharge relation at a site. In either case, the
same test method is followed for obtaining field data and
computation of discharge.

1.4 Measurements for the purpose of determining the discharge in efficiency tests of hydraulic turbines are specified in
International Electrotechnical Commission Publication 413 for
the field acceptance tests of hydraulic turbines, and is not
included in this test method.

1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.