4210 Flow Meter
Section 2 Programming
2-32
2.7.2 Equation Returning to step 2, SELECT FLOW CONVERSION: If you
select EQUATION, the following will appear:
This step allows you to enter an equation that is appropriate for
your flow situation. The equation is expressed in the general
form of Q = k1H
P1
+ k2H
P2
, where Q = flow rate, k1 = a constant,
H = level or head, and P1 is the power to which H is raised. k2
and P2 are a second constant and power found in some equa-
tions. If your equation has only one term, you should enter 0 for
the second constant.
2.7.3 Manning Conversion Again returning to step 2, SELECT FLOW CONVERSION, if
you select MANNING, the following display will appear:
TRAPEZOIDAL is also available, if you move to the right with
the right arrow key.
If you select ROUND PIPE for the Manning flow conversion, the
following displays will appear:
Slope is entered as a dimensionless quantity, delta Y/ delta X, not
as percent slope. Or, as otherwise expressed:
For example:
Roughness coefficients are published in the Isco Open Channel
Flow Measurement Handbook. You must know the material the
pipe is made of. The roughness coefficients are published for all
common materials in three grades: minimum, normal, and
maximum. Then:
If you select U-CHANNEL for the Manning flow conversion, the
following displays will appear:
(Slope and roughness are entered as for ROUND PIPE.) Then:
ENTER EQUATION UNITS
Q = XXX.XXXH^X.XX + XXX.XXXH^X.XX
SELECT MANNING TYPE
• ROUND PIPE • • U-CHANNEL • • RECTANGULAR • • T–
MANNING ROUND PIPE
SLOPE = X.XXXXX ROUGH = X.XXXX
MANNING ROUND PIPE
DIAMETER = X.XXX FEET (or meters)
MANNING U-CHANNEL
SLOPE = X.XXXXX ROUGH = X.XXX
MANNING U-CHANNEL
WIDTH = X.XXX FEET (or meters)
X∆
Y∆
--------
Rise
R
un
-----------=
1
100
--------- 0.01=
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