ADS Environmental Services Portable FlowShark Pulse QR 775006 A2 - Manual (Page 43)

3-6 ADS Portable FlowShark Pulse Manual
 Error! Installed in draw-down, transitioning from flowing to
falling
Depth measurement may fail and velocity and depth
measurement may be erroneous
? Critical measurement point, not recommended! Flow
begins to fall (or sink)
 Distance l = min. 5 x h
max
at location of installation
Error caused by changes in flow profile before slope fluctuation or fall
(1) Equipment such as samplers or similar devices
(2) Obstruction
 Error! Caused by vorticity, peripheral flow, and/or
asymmetric flow
 Distance l
1
(upstream of obstruction) = min. 5 x h
max
Distance l
2
(downstream of obstruction) = min. 10 x h
max
in case of flow velocities >3.3 ft/s (1 m/s)
Errors caused by equipment or obstructions