General Instructions - Global Water FP101 User Manual

III. General Instructions
a. Make sure the Flow Probe's propeller turns freely by blowing strongly
on the prop.
b. Point the propeller directly into the flow you wish to measure. Face the
arrow inside the prop housing downstream. The FP101 probe handle
is a two piece rod expandable from 3' to 6', and the FP201 is a three
section rod expandable from 5' to 15'. To expand the rod for correct
placement in flow, loosen the locking nut on the handle, pulling out the
top piece and retightening the nut.
c. Use the bottom button to scroll through the functions until
"AVGSPEED" appears. The top number is the instantaneous velocity
to the nearest .5 ft/second. The lower display is the average velocity.
Pressing the top button for 3 seconds will clear the average and start a
new reading. While taking an average reading the maximum velocity
will also be recorded. Pushing the bottom button until "MAXSPEED" is
displayed causes the lower display to indicate this value. While on this
screen, pressing the top button for 3 seconds will clear this value.
While on the average or maximum screens pressing the top button for
5 seconds will clear both of these functions.
d. To make a measurement, place the propeller at the desired measuring
point and hold the top button for 3 seconds to clear the value or 5
seconds to clear both average and maximum values. Hold the probe
in place until the reading becomes steady and remove the probe from
the water. The average and maximum velocities remain in their
respective screens. These values are only updated while the propeller
is turning. See the Average Velocity section for more information.
e. Measure/calculate the cross-sectional area of your flow stream in
square feet. If you are measuring flow in round pipes, measure the
depth of water and use the enclosed tables to determine cross-
sectional area (see Appendix B: Calculations for Flow in Partially Filled
Pipes). If you are measuring flow in another channel type, manually
measure water depth at several points across the flow. These
measurements are most easily recorded by drawing a diagram on
graph paper with a scale of 1 square foot per graph paper square.
Cross-sectional area (in square feet) can then be found by counting
the number of squares in the stream.
Global Water
800-876-1172 • globalw.com
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