Mace HydroMace XCi, Руководство по эксплуатации продукта, Страница: 194 / 270

"Flowrate (using trickle flow)" - channel type
This channel uses the Mannings formula to calculate velocity in a circular pipe based upon depth
measurement from a MACE Area/Velocity sensor.
The Mannings equation, uses an algorithm to derive the " Velocity " of flow in a pipe based on depth, pipe
gradient and a "roughness coefficient".
V = (CoEff / N) R
h
2/3
.S
1/2
Where:
V = Stream Velocity (ft/s, m/s)
CoEff = 1.49 for US units and 1.0 for metric units
N = Mannings roughness co-efficient (unitless)
R
h
= Hydraulic Radius (ft, m)
S
= Pipe slope (ft/ft, m/m).
WARNING: There are inherent inaccuracies with using the Mannings equation for
calculating " Velocity ". User should make themselves aware of the limitations of this
method PRIOR to use.
Add a "Flowrate (using trickle flow)" - channel type
NOTE: The XCi implementation of the Mannings equation into a " Flowrate (using
trickle flow) " channel uses the derived " Velocity " measurement used in conjunction
with the " Depth " measurement ONLY from a MACE A/V Doppler sensor. A " Flowrate
(using trickle flow) " - channel type can only be added after suitable Doppler "Velocity
and "Depth" channels have been added to the configuration.
1. After selecting the "" Flowrate (using trickle flow) " channel type and naming the new channel, the
" Select velocity channel " dialogue box will appear prompting you to use the drop down list to
highlight the " Velocity channel " from which the new " Flowrate (using trickle flow) channel " will
receive its value.
2. Click “ Continue ” and the “ Select depth channel ” dialogue box will appear. In the “ Select depth
channel ” dialogue box use the drop down list to highlight the " Depth " channel from which the
" Flowrate (using trickle flow) " channel named will receive its value. Click “ Continue ” to complete
MACE XCi User Manual - 194 -