1 - AS 3778.4.1-1991 MEASUREMENT WATER FLOW IN OPEN CHANNELS - MEASUREMENT USING FLOW GAUGING STRUCTURES - THIN-PLATE WEIRS
4 - PREFACE
6 - 1 SCOPE AND FIELD OF APPLICATION
6 - 2 REFERENCES
6 - 3 DEFINITIONS
6 - 4 UNITS OF MEASUREMENT
6 - 5 PRINCIPLE
6 - 6 INSTALLATION
6 - 6.1 General
6 - 6.2 Selection of site
6 - 6.3 Installation conditions
6 - 6.3.1 General
6 - 6.3.2 Weir
6 - 6.3.3 Approach channel
8 - 6.3.4 Downstream channel
8 - 7 MEASUREMENT OF HEAD
8 - 7.1 Head measuring devices
8 - 7.2 Stilling well
8 - 7.3 Head-measurement section
8 - 7.4 Head-gauge datum (gauge zero)
8 - 8 MAINTENANCE
8 - 9 RECTANGULAR THIN-PLATE WEIR
8 - 9.1 Types
10 - 9.2 Specifications for the standard weir
10 - 9.3 Specifications for installation
10 - 9.4 Specifications for head measurement
10 - 9.4.1 General
10 - 9.4.2 Determination of gauge zero
10 - 9.5 Discharge formulae – General
12 - 9.6 Formulae for the basic weir form (all values of b/B)
12 - 9.6.1 Kindsvater-Carter formula
13 - 9.6.2 SIA formula
14 - 9.7 Formulae for full-width weirs (b/B=1,0)
14 - 9.7.1 Rehbock formula (1929)
14 - 9.7.2 IMFT formula
14 - 9.8 Accuracy of discharge coefficient – Rectangular weirs
14 - 10 TRIANGULAR- NOTCH THIN-PLATE WEIR
14 - 10.1 Specifications for the standard weir
16 - 10.2 Specifications for the installation
16 - 10.3 Specifications for head measurement
16 - 10.3.1 General
16 - 10.3.2 Determination of notch angle
16 - 10.3.3 Determination of gauge zero
16 - 10.4 Discharge formulae – General
17 - 10.5 Formula for all notch angles between pi/9 and 5 pi/9 radians (20° and 100°)
17 - 10.5.1 Evaluation of Ce and kh
18 - 10.5.2 Practical limitations on alpha, h/p, p/B, h and p
18 - 10.6 Formula for specific notch angles (fully-contracted weir)
19 - 10.7 Accuracy of discharge coefficients – Triangular-notch weirs
19 - 11 ACCURACY OF DISCHARGE MEASUREMENTS
19 - 11.1 General
19 - 11.2 Sources of error
19 - 11.3 Uncertainties due to different kinds of errors
19 - 11.4 Errors in recommended coefficients
20 - 11.5 Errors in quantities measured by the user
20 - 11.6 Combination of uncertainties
20 - 12 EXAMPLES OF UNCERTAINTY CALCULATIONS
20 - 12.1 Rectangular weir
21 - 12.1.1 Uncertainties given in this calculation
21 - 12.1.2 Uncertainties estimated by the user
21 - 12.1.3 Calculated uncertainties
21 - 12.2 Triangular-notch weir
21 - 12.2.1 Uncertainties given in this calculation
21 - 12.2.2 Uncertainties estimated by the user
21 - 12.2.3 Calculated uncertainties
31 - ANNEX - GUIDE FOR THE SELECTION OF WEIRS AND FLUMES FOR THE MEASUREMENTOF THE DISCHARGE OF WATER IN OPEN CHANNELS
31 - A.1 SCOPE AND FIELD OF APPLICATION
31 - A.2 TYPES OF STANDARD WEIRS AND FLUMES
31 - A.3 CRITERIA FOR THE SELECTION OF STANDARD WEIRS OR FLUMES