YSI 600LS - User Manual - Manual (Page 321)

Flow Appendix F
YSI Incorporated Environmental Monitoring Systems Operations Manual F-2
Method Type Size
Weir V-Notch 22½
°, 30°, 45°, 60°, 90°, 120°
Rectangular w/ End Contractions Any size
Rectangular w/o End Contractions Any size
Cipolletti Any size
Flume Parshall 1”, 2”, 3”, 6”, 9” 12”, 18”, 2’, 3’, 4’, 5’, 6’, 8’, 10’, 12’
Palmer-Bowlus 4”, 6”, 8”, 10”, 12”, 15”, 18”, 21”, 24”, 27”, 30”
Leopold-Lagco 4”, 6”, 8”, 10”, 12”, 15”, 18”, 21”, 24”, 30”
Trapezoidal Large 60
° V, X-large 60° V, 2” 45° WSC,
12” 45
° SRCRC
Hs 0.4ft, 0.6ft, 0.8ft, 1ft,
H 0.5ft, 0.75ft, 1 ft, 1.5ft, 2ft, 2.5ft, 3 ft, 4.5 ft
HL 4 ft
After selecting the method, type and size of primary device, YSI strongly recommends that you verify that
the sonde is set up properly. Find a chart that lists head versus flow for your primary measuring device.
From the Flow Setup menu choose Test Flow. Then choose the units and flow units that are on your chart.
Enter a few values for Test Head and compare the resulting Test Flow values against those found in the
chart. Note that there may be minor differences in the least significant digit between the published values
and the values given by the sonde. The difference is generally much less than the overall tolerance of the
weir or flume being used.
The final step is to return to the Report menu and choose the flow and volume units you wish to have in
the report. Note that the units in the report menu are independent of the units in the Flow Setup menu.
MANNING EQUATION
Once in the Flow Setup menu, choose Manning for the Method and then choose which type of channel the
measurement is to be done in: closed pipe, U- channel, rectangular, or trapezoidal. Then choose the units
for the equation. It is very important that the units chosen match the coefficients for the equation. Finally
choose Setup Manning and define the width of the channel, its roughness and slope. Roughness is given in
many fluid hydraulics texts and other engineering references as the Manning coefficient, n. Empirical
values for n are given in the same references for most commonly found materials used in open channel
construction. Slope is the ratio of rise to run. For example, if a channel drops one foot every one hundred
feet, the value of the slope would be 0.01.
After setting up the Manning Equation, we strongly recommend that you verify that the sonde is set up
properly. From the Flow Setup menu choose Test Flow. Then choose the units and flow units that you
prefer. Enter a few values for Test Head and judge whether the resulting Test Flow values are reasonable.
You might even want to try doing the calculation yourself.