ULTRATWIN (UL)
INSTRUCTION MANUAL
72
Flow
If you want to set-up a
flow
application, as described in the following
examples, then choose 3
for
flow
. You will then be given a choice of
Primary Measuring Devices
to choose from.
Choose Your Application
There are five categories of
P
rimary
M
easuring
D
evice, which are all
described in this chapter. They are
exponential
,
BS3860 flumes
,
BS3860
weirs, special and universal.
Calculations for flow can be performed using absolute or ratiometric
calculations. The answer will be the same, the choice of calculation method
being limited to the amount of information available, with regards to the
primary measuring device.
For ratiometric calculation it is normally sufficient to know the maximum
flow at maximum head for the device in question. All types of primary
measuring devices can be set up with a choice of alarms.
If you want to set-up a basic
exponential device
, as described in the
following
example 1
, then choose
3
for
Flow
, followed by
1
for
exponent
.
You then need to select the
primary measuring device
for your application
from the following available options:
suppressed rectangular weir
,
Cipolletti (trapezoidal) weir
,
Venturi flume,
Parshall flume
,
Leopold
Lagco flume
,
V notch weir
or
other,
for any other type of
exponential
device.
To set-up an application for a
BS3680 flume
, as described in the following
example 2
, then choose
3
for
Flow
followed by
2
for
3680 Flume
. You then
need to select the
primary measuring device
for your application from the
following available options:
rectangular flume with
or
without hump
,
U-
throated flume with
or
without hump
.
To set-up an application for a
BS3680 weir
, as described in the following
example 3
, then choose
3
for
Flow
followed by 3 for 3680 Weir. You then
need to select the
primary measuring device
for your application from the
following available options:
rectangular weir
,
V notch full 90
o
(90degrees)
,
V notch half 90
o
(53 degree 8 minutes),
V notch quarter 90
o
(28 degree
4 minutes)
or a
Broad Crested Weir
.
