AS 3778.4.6-1991

1 - AS 3778.4.6-1991 MEASUREMENT OF WATER FLOW IN OPEN CHANNELS - MEASUREMENT USING FLOW GAUGING STRUCTURES - FLAT-V WEIRS
4 - PREFACE
6 - 1 Scope
6 - 2 General
6 - 3 Normative references
6 - 4 Definitions and symbols
6 - 5 Installation
6 - 5.1 Selection of site
7 - 5.2 Installation conditions
7 - 5.2.1 General requirements
7 - 5.2.2 Approach channel
9 - 5.3 Weir structure
9 - 5.4 Downstream of the structure
9 - 6 Maintenance - General requirements
9 - 7 Measurement of head(s)
9 - 7.1 General requirements
9 - 7.2 Gauge wells
10 - 7.3 Zero setting
10 - 7.4 Location of head measurement sections
11 - 8 Discharge relationships
11 - 8.1 Discharge equation
11 - 8.2 Discharge coefficient
11 - 8.3 Velocity of approach factor
12 - 8.4 Shape factor
12 - 8.5 Drowned flow reduction factor
12 - 8.6 Limits of application
15 - 9 Computation of discharge
15 - 9.1 Computation steps
15 - 9.2 Accuracy
15 - 10 Errors in flow measurement
15 - 10.1 General
15 - 10.2 Sources of error
16 - 10.3 Types of error
16 - 10.4 Errors in quantities given in this Inter-The national Standard
17 - 10.5 Errors in quantities measured by the user
17 - 10.6 Combination of uncertainties
17 - 10.7 Presentation of results
17 - 11 Examples
17 - 11.1 Modular flow at low discharge
17 - 11.1.1 Basic data
17 - 11.1.2 Calculation of discharge
18 - 11.1.3 Random uncertainty in calculated discharge
18 - 11.1.4 Systematic uncertainty in calculated discharge
18 - 11.1.5 Total uncertainty in the discharge
18 - 11.2 Drowned flow at high discharge
18 - 11.2.1 Basic data
18 - 11.2.2 Calculation of discharge
19 - 11.2.3 Random uncertainty in calculated discharge
19 - 11.2.4 Systematic uncertainty in calculated discharge
19 - 11.2.5 Total uncertainty in the discharge
20 - Annex A - Nomenclature
21 - Annex B - Velocity distribution
23 - Annex C - Bibliography