1 - AS 3778.3.4-1990 MEASUREMENT OF WATER FLOW IN OPEN CHANNELS - VELOCITY-AREA METHODS - COLLECTION AND PROCESSING OF DATA...
4 - PREFACE
6 - 1 Scope and field of application
6 - 2 References
6 - 3 General
6 - 3.1 Principle
6 - 3.2 Occurrence of error
7 - 3.3 Sources of error
7 - 3.4 Determination of the individual components of the error
7 - 3.4.1 Errors in width
7 - 3.4.2 Errors in depth
7 - 3.4.3 Errors in determination of the mean velocity
8 - 3.4.4 Symbols
8 - 3.5 Description of the uncertainty
8 - 3.6 Total uncertainty in discharge
9 - 3.7 Evaluation of the error in the individual components
9 - 4 Data on the local point velocity
9 - 5 Data on the average velocity
9 - 5.1 Location of the vertical
9 - 5.2 Distribution of measuring points
10 - 5.3 Period of measurement of local point velocities
10 - 5.4 Number of measurements
10 - 5.5 Presentation of data
10 - 6 Data on the velocity-area method
10 - 6.1 Measurement at 0,6 times the depth
10 - 6.2 Velocity-distribution method
10 - 6.3 Presentation of data
10 - 6.4 General data
10 - 7 Integration method
11 - 8 Calibration curves
11 - 9 Distance measurements
11 - 10 Depth measurements
11 - 11 Data processing
11 - 11.1 General
11 - 11.2 Error-type I
11 - 11.2.1 Finite measuring time and distribution of results
11 - 11.2.2 Correction for non-steady conditions
12 - 11.2.3 Standard deviation of velocity fluctuations
12 - 11.2.4 Autocorrelation function
12 - 11.2.5 Effect of measuring time on standard deviation (1)
12 - 11.2.6 Effect of measuring time on standard deviation (2)
13 - 11.2.7 Compilation of results
13 - 11.3 Error-type II
13 - 11.3.1 Approximation of mean velocity in the vertical
13 - 11.3.2 Determination of the standard mean velocity in the vertical
13 - 11.3.3 Computation methods
13 - 11.3.4 Sampling error due to velocity fluctuations and computation rule
14 - 11.3.5 Sampling error due to computation rule
14 - 11.4 Error-type III
14 - 11.4.1 Restricted number of verticals
14 - 11.4.2 True discharge
14 - 11.4.3 Omission of verticals
14 - 11.4.4 Mean and standard deviations of error
15 - 11.4.5 Criteria applied in choosing the verticals
15 - 12 List of symbols
18 - Annex A - Local point velocity measurements - Report form
21 - Annex B - Average velocity measurements – Report form
24 - Annex C - Velocity-area method – Report form