Mace HVFlo XCi, Product Manual

Page: 171 / 255

Flowrate units
Select the units and the timebase from the drop down list boxes. This sets the units on the logged value.
Polynomial coefficients
The polynomial coefficients listed i are related to the following equation:
Cross-Sectional Area = A + B*X +C*X
2
+ D*X
3
+ E*X
4
+ F*X
5
Where X = depth of stream The coefficients are listed in order A, B, C, D, E, F.
Siltation depth
This parameter can be used to correct the calculated flow rate if a known amount of silt is inside the pipe. The
depth of silt will be subtracted from the area calculation in order to calculate the corrected flow rate.
Depth limit
When the cross-sectional area of a stream is calculated using the polynomial coefficient method, the user
must set the “
Depth limit
” at which the polynomial reaches a maximum. For example, if a channel has a
maximum depth of 1.0m the “
Depth limit
” should be set at 1.0m as well. Alternatively the “
Depth limit
” can
be set within
FloCalc
and the procedure described for importing polynomial coefficients.
Import parameters from FloCalc
If the user does not know the coefficients for the polynomial equation, they can be calculated using the
MACE utility " FloCalc "
Using MACE "FloCalc" to calculate polynomial coefficients
The Mace utility program " FloCalc " (download separately from www.macemeters.com) can be used to draw
regular and irregular channel shapes. These shapes are then converted into a 5th order polynomial. Their
coefficients can be imported directly into the appropriate fields in
MACE XCi User Manual - 171 -