ASTM D5640-95(2003)

Standard Guide for Selection of Weirs and Flumes for Open-Channel Flow Measurement of Water

SIGNIFICANCE AND USE
Each type of weir and flume possesses advantages and disadvantages relative to the other types when it is considered for a specific application; consequently, the selection process often involves reaching a compromise among several features. This guide is intended to assist the user in making a selection that is hydraulically, structurally, and economically appropriate for the purpose.
It is recognized that not all open-channel situations are amenable to flow measurement by weirs and flumes and that in some cases, particularly in large streams, discharges may best be determined by other means. (See 6.2.2.)
SCOPE
1.1 This guide covers recommendations for the selection of weirs and flumes for the measurement of the volumetric flow rate of water and wastewater in open channels under a variety of field conditions.
1.2 This guide emphasizes the weirs and flumes for which ASTM standards are available, namely, thin-plate weirs, broad-crested weirs, Parshall flumes, and Palmer-Bowlus (and other long-throated) flumes. However, reference is also made to other measurement devices and methods that may be useful in specific situations.
1.3 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.

General Information

• Status: Historical
• Publication Date: 09-Jun-2003
• Technical Committee: D19 - Water
• Drafting Committee: D19.07 - Sediments, Geomorphology, and Open-Channel Flow

Relations

• Replaces: ASTM D5640-95(1999) - Standard Guide for Selection of Weirs and Flumes for Open-Channel Flow Measurement of Water
• Effective Date: 10-Jun-2003
• Replaced By: ASTM D5640-95(2008) - Standard Guide for Selection of Weirs and Flumes for Open-Channel Flow Measurement of Water
• Effective Date: 01-Oct-2008
• Referred By: ASTM C1745/C1745M-18 - Standard Test Method for Measurement of Hydraulic Characteristics of Hydrodynamic Stormwater Separators and Underground Settling Devices
• Effective Date: 10-Jun-2003
• Referred By: ASTM D4410-16 - Terminology for Fluvial Sediment
• Effective Date: 10-Jun-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D5640–95(Reapproved2003)
Standard Guide for
Selection of Weirs and Flumes for Open-Channel Flow
1
Measurement of Water
This standard is issued under the fixed designation D 5640; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of 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.
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1. Scope Flow—Constant-Rate Injection Method
1.1 This guide covers recommendations for the selection of
3. Terminology
weirs and flumes for the measurement of the volumetric flow
3.1 Definitions—For definitions of terms used in this guide,
rate of water and wastewater in open channels under a variety
refer to Terminology D 1129.
of field conditions.
3.2 Definitions of Terms Specific to This Standard:
1.2 This guide emphasizes the weirs and flumes for which
3.2.1 blackwater—anincreaseinthedepthofflowupstream
ASTMstandardsareavailable,namely,thin-plateweirs,broad-
of a channel obstruction, in this case a weir or flume.
crested weirs, Parshall flumes, and Palmer-Bowlus (and other
3.2.2 contracted weirs—contractions of thin-plate weirs
long-throated) flumes. However, reference is also made to
refer to the widths of weir plate between the notch and the
other measurement devices and methods that may be useful in
sidewalls of the approach channel. In fully contracted weirs,
specific situations.
the ratio of the notch area to the cross-sectional area of the
1.3 This standard does not purport to address all of the
approach channel is small enough for the shape of the channel
safety concerns, if any, associated with its use. It is the
to have little effect. In suppressed (full-width) rectangular
responsibility of the user of this standard to establish appro-
weirs, the contractions are suppressed, and the weir crest
priate safety and health practices and determine the applica-
extends the full width of the channel.
bility of regulatory limitations prior to use.
3.2.3 crest—in rectangular thin-plate weirs, the horizontal
2. Referenced Documents bottom of the overflow section; in broad-crested weirs and
flumes, the plane, level floor of the flow section.
2.1 ASTM Standards:
2
3.2.4 critical flow—open-channel flow in which the energy,
D 1129 Terminology Relating to Water
expressed in terms of depth plus velocity head, is a minimum
D 1941 Test Method for Open Channel Flow Measurement
2 for a given flow rate and channel.
of Water with the Parshall Flume
3.2.4.1 Discussion—The Froude number is unity at critical
D 3858 Test Method for Open-Channel Flow Measurement
2 flow.
of Water by Velocity-Area Method
3.2.5 Froude number—a dimensionless number expressing
D 5242 Test Method for Open-Channel Flow Measurement
2 the ratio of inertial to gravity forces in free-surface flow. It is
of Water with Thin-Plate Weirs
equal to the average velocity divided by the square root of the
D 5389 Test Method for Open-Channel Flow Measurement
2 product of the average depth and the acceleration due to
of Water by Acoustic Velocity Meter Systems
gravity.
D 5390 Test Method for Open-Channel Flow Measurement
2 3.2.6 head—in this context, the depth of flow referenced to
of Water with Palmer-Bowlus Flume
the crest of the weir or flume and measured at a specified
D 5614 Test Method for Open-Channel Flow Measurement
2
location; this depth plus the velocity head are often termed the
of Water with Broad-Crested Weirs
total head or total energy head.
2.2 ISO Standard:
3.2.7 hydraulic jump—an abrupt transition from supercriti-
ISO 555-1973: Liquid Flow Measurement in Open
caltosubcriticalortranquilflow,accompaniedbyconsiderable
Channels—Dilution Methods for Measurement of Steady
turbulence or gravity waves, or both.
3.2.8 long-throated flume—a flume in which the prismatic
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throat is long enough, relative to the head, for a region of
This guide is under the jurisdiction of ASTM Committee D19 on Water and is
the direct responsibility of Subcommittee D19.07 on Sediments, Geomorphology,
essentially critical flow to develop on the crest.
and Open-Channel Flow.
Current edition approved June 10, 2003. Published August 2003. Originally
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approved in 1995. Last previous edition approved in 1999 as D 5640 – 95 (1999). Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
2
Annual Book of ASTM Standards, Vol 11.01. 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D5640–95 (2003)
3.2.9 nappe—the curved sheet or jet of water overfalling a
weir.
3.2.10 notch—theoverflowsectionofatriangularweirorof
a rectangular weir with side contractions.
3.2.11 primary instrument—the devi
...