Teledyne 4250 Installation And Operation Manual page 67

Returning to Step 2, SELECT FLOW CONVERSION, if you
select MANNING, the following will appear:
SELECT MANNING TYPE
• ROUND PIPE • • U-CHANNEL, RECTANGULAR • • T–
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:
MANNING ROUND PIPE
SLOPE = X.XXXXX ROUGH = X.XXXX
Slope is entered as a dimensionless quantity, delta Y/ delta X, not
as percent slope. Or, as otherwise expressed:

X
Y
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:
MANNING ROUND PIPE
DIAMETER = X.XXX FEET (or meters)
If you select U-CHANNEL for the Manning flow conversion, the
following displays will appear:
MANNING U-CHANNEL
SLOPE = X.XXXXX ROUGH = X.XXX
(
Slope and roughness are entered as for ROUND PIPE previ-
ously.) Then:
MANNING U-CHANNEL
WIDTH = X.XXX FEET (or meters)
If you select RECTANGULAR for the Manning flow conversion,
the following displays will appear:
MANNING RECTANGULAR
SLOPE=X.XXXXX ROUGH=X.XXX
4250 Flow Meter
Section 2 Programming
Rise
=
Run
1
= .01
100
2-39