Page 101
Choose Your Application
There are six categories of Primary Measuring Device, which are all
described in this chapter. They are exponential, BS3860 flumes, BS3860
weirs, area/velocity, 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 1. 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 2. 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. 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) or a V notch quarter 90
o
(28 degree 4 minutes).
To set-up an application for area velocity, then choose 4. You then need to
select the primary measuring device for your application from the
following available options: U-channel (circular bottom with straight sides),
rectangular channel, trapezoidal channel or a round pipe.
To set-up an application for a device contained in special, choose 5. You
then need to select the primary measuring device for your application from
the following available options: Palmer Bowlus flume, H-flume or a V
notch, other than BS3680.
To Next Page
Loading...
