Xylem SonTek FlowTracker2, User Manual

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SonTek – a Xylem brand
FlowTracker2 User’s Manual (January 2019) 300
Appendix B. Site Selection Requirements
The Site Selection Requirements for performing discharge measurements using a
FlowTracker2 instrument are based on a number of measurement site and hydraulic
requirements. The measurement site and hydraulic requirements are similar to what a
Hydrologists or Hydrographer will use in the selection of monitoring site for either
natural or artificial control. The site and hydraulic requirements that need to be taken in
into account with every discharge measurement are summarized under the following
points.
a) Uniform flow conditions throughout the measurement section,
b) Straight length of channel with uniform cross-section and slope (10 times section
width).
c) Flow in the channel should be confined to a single well-defined channel with
stable banks.
d) Avoid a site with wide shallow sections or secondary side channels.
e) Bends upstream of site should be avoided as this will result in angular flow
towards tagline,
f) Steep slopes upstream should be avoided as this could result in high approach
velocities at the measurement site causing turbulent flow conditions.
g) Avoid measurement sections with deep pools as the reduction in velocity
normally diverge from uniform flow conditions,
h) Avoid prominent obstructions in a pool or excessive plant growth that can affect
the flow pattern.
i) Turbulent flow conditions should be avoided if possible.
j) Negative and or back flow should be avoided at all times.
k) Flow conditions must be within the instrument and equipment specifications