ULTRA 4 INSTRUCTION MANUAL 
 
76 
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 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 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.