Marsh-McBirney Flo-Mate 2000 - The.2,.4,.8 Method; The.4 Method; The 0.9 X Vmax Method; The VPT Method

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The .2, .4, .8 Method
(5.4 + 5.35) ÷ 2 = 5.37 ft/sec
= (5.37 +5.5) ÷ 2 = 5.44 ft/sec
The .4 Method
The velocity at the .4 position = 5.5 ft/sec.
= 5.5 ft/sec.
The 0.9 x Vmax Method
Vmax = 5.5 ft/sec.
= 0.9 x 5.5 = 4.95 ft/sec
The 2-D Method
Average all velocity measurements. Remember to include the two corner measurements and discard
any outliers.
= 4.8 ft/sec
The VPT Method
This method requires a computer program. If you have this program, enter the velocity measure-
ments from the center line profile. Discard any outliers.
from VPT program = 5.32 ft/sec
Average
An overall can be calculated by averaging the values from the different methods.
(5.44 + 5.5 + 4.95 + 5.0 + 5.32) ÷ 5 = 5.24 ft/sec
Comment:
If the profile is not symmetrical, then the results from the .9 x Vmax and 2-D methods may vary
greatly from the VPT; .2, .4, .8; and .4 methods.
POSITION VELOCITY
.2 x 7" = 1.4" . 5.4 ft/sec
.4 x 7" = 2.8" . 5.5 ft/sec
.8 x 7" = 5.35" . 5.35 ft/sec
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