Header
About this publication
Preface
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Flume types and principles of operation
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
6 Installation
6.1 Selection of site
6.1.1
6.1.2
6.1.3
6.1.4
6.1.5
6.1.6
6.1.7
6.1.8
6.1.9
6.2 Installation conditions
6.2.1 General requirements
6.2.1.1
6.2.1.2
6.2.1.3
6.2.1.4
6.2.2 Flume structure
6.2.2.1
6.2.2.2
6.2.2.3
6.2.2.4
6.2.3 Approach channel
6.2.3.1
6.2.3.2
6.2.4 Downstream conditions
6.2.4.1
6.2.4.2
7 Maintenance
7.1
7.2
7.3
7.4
8 Measurement of head
8.1 General
8.1.1
8.1.2
8.2 Location of head measurement(s)
8.2.1
8.2.2
8.2.3
8.3 Gauge wells
8.3.1
8.3.2
8.3.3
8.3.4
8.3.5
8.3.6
8.4 Zero setting
8.4.1
8.4.2
8.4.3
8.4.4
9 General formulae for discharge
9.1 Discharge based on critical flow in the flume throat
9.1.1
9.1.2
9.1.3
9.1.4
9.1.5
9.1.6
9.2 Discharge based on observed upstream head
9.2.1
9.2.2
9.2.3
9.2.4
9.2.5
9.2.6
9.2.7
9.2.8
9.2.9
9.2.10
9.2.11
9.2.12
9.3 Calculation of stage–discharge relationships
9.3.1
9.3.2
9.3.3
9.4 Approach velocity and coefficient of velocity
9.4.1
9.4.2
9.4.3
9.4.4
9.4.5
9.4.6
9.5 Selection of flume size and shape
10 Rectangular-throated flume
10.1 Description
10.1.1
10.1.2
10.1.3
10.1.4
10.1.5
10.2 Location of head measurement section
10.3 Provision for modular flow
10.3.1
10.3.2
10.3.3
10.4 Evaluation of discharge for a given observed upstream head
10.4.1
10.4.2
10.4.3
10.4.4
10.4.5
10.4.6
10.4.7
10.4.8
10.4.9
10.4.10
10.4.11
10.4.12
10.4.13
10.5 Computation of stage–discharge relationship
10.5.1
10.5.2
10.6 Limits of application
10.6.1
10.6.2
10.6.3
10.6.4
10.6.5
10.6.6
11 Trapezoidal-throated flumes
11.1 Description
11.1.1
11.1.2
11.1.3
11.1.4
11.1.5
11.1.6
11.2 Location of head measurement section
11.3 Provision for modular flow
11.3.1
11.3.2
11.3.3
11.3.4
11.4 Evaluation of discharge — Coefficient method
11.4.1
11.4.2
11.4.3
11.4.4
11.4.5
11.4.6
11.4.7
11.4.8
11.4.9
11.4.10
11.4.11
11.4.12
11.4.13
11.5 Computation of stage–discharge relationship
11.5.1
11.5.2
11.5.3
11.5.4
11.5.5
11.5.6
11.5.7
11.5.8
11.5.9
11.6 Limits of application
11.6.1
11.6.2
11.6.3
11.6.4
11.6.5
11.6.6
12 U-throated (round-bottomed) flumes
12.1 Description
12.1.1
12.1.2
12.1.3
12.1.4
12.1.5
12.2 Location of head measurement section
12.3 Provision for modular flow
12.3.1
12.3.2
12.3.3
12.3.4
12.4 Evaluation of discharge — Coefficient method
12.4.1
12.4.2
12.4.3
12.4.4
12.4.5
12.4.6
12.4.7
12.4.8
12.4.9
12.4.10
12.4.11
12.4.12
12.4.13
12.5 Computation of stage–discharge relationship
12.5.1
12.5.2
12.5.3
12.5.4
12.5.5
12.5.6
12.5.7
12.5.8
12.5.9
12.6 Limits of application
12.6.1
12.6.2
12.6.3
12.6.4
12.6.5
12.6.6
12.6.7
13 Uncertainties of flow measurement
13.1 General
13.1.1
13.1.2
13.1.3
13.1.4
13.1.5
13.2 Combining measurement uncertainties
13.2.1
13.2.2
13.2.3
13.2.4
13.2.5
13.2.6
13.2.7
13.2.8
13.3 Percentage uncertainty of discharge coefficient u*(C) for critical-depth flumes
13.4 Uncertainty budget
13.4.1
13.4.2
14 Example of uncertainty calculations
14.1 General
14.1.1
14.1.2
14.2 Characteristics — Gauging structure
14.3 Characteristics — Discharge calculation
14.4 Characteristics — Discharge coefficient
14.5 Characteristics — Gauged head instrumentation
14.5.1
14.5.2
14.5.3
14.6 Characteristics — Throat width
14.6.1
14.6.2
14.6.3
14.6.4
14.6.5
14.7 Overall uncertainty in discharge
14.7.1
14.7.2
14.7.3
14.7.4
14.7.5
Annex A
Annex B
B.1 General
B.2 Confidence limits and coverage factors
B.3 Random and systematic error
B.4 Measurement standards
B.5 Evaluation of Type-A uncertainty
B.6 Evaluation of Type-B uncertainty
B.6.1 General
B.6.2 The triangular distribution
B.6.3 The rectangular distribution
B.6.4 Normal (Gaussian) probability distribution
B.6.5 The bimodal probability distribution
B.7 Combined uncertainty value, uc
Annex C
Annex D
D.1 General
D.2 Structure of spreadsheets
Bibliography
