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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 Primary Measuring Device, 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.
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