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Chapter 4 - Experimental setup and test procedure
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1. Measurement frame
2. Discharge controller
3. Frame controller
4. Level acquisition
5. Velocity acquisition
6. Levelling probe
7. Velocity probe and support
8. Fixation of the frame
Figure 4.17: Picture of the data acquisition system and the used probes
4.4.2 Central command unit and frame command unit
The central command unit (Appendix 2.2.1) read a command file and executed the instructions
like the frame position, measurements to perform (water or bed levels, velocities) and duration of
each measurement (see Fig. 4.18). A track of the executed commands as well as the reached frame
positions were written to a log file. The central command program (Labview 5.1) sent small data
packages with the instructions to the different computers, where the information was introduced
by means of a small Visual Basic program (VB 5.1) into the final data acquisition program. It was
possible to track the overall progress of the data acquisition on a remote computer.
The frame positions are given on Fig. 4.19. The automatic measurements were limited to the bend
(positions 4 to 9) and the first 2 meters next to the curve (positions 3 and 10).
page 84 / November 9, 2002
Wall roughness effects on flow and scouring