Dynasonics TFX Ultra Transit Time Flow Meters User Manual
Page 98
Find the area of the pipe cross section.
2
3.068
2
Area = πr
2
Area = π
= π x 2.35 = 7.39 in
2
Find the volume in one foot of travel.
88.71in
2
7.39 in
2
x 12 in. (1 ft)
ft
=
What portion of a gallon does one foot of travel represent?
= 0.384 gallons
88.71 in
3
231 in
3
So for every foot of fluid travel 0.384 gallons will pass.
What is the flow rate in gpm at 4.3 ft/sec?
0.384 gallons × 4.3 FPS × 60 sec (1 min) = 99.1 gpm
Now that the volumetric flow rate is known, all that is needed is an output frequency to determine the K factor.
Known values are:
Frequency
=
700 Hz (By measurement)
Flow Rate
=
99.1 gpm (By calculation)
700 Hz × 60 sec = 42,000 pulses per gallon
K factor
42,000 pulses per min
99.1 gpm
423.9 pulses per gallon
=
=
K FACTORS EXPLAINED
Page 98
March 2014