V-notch angle weirs, the head is measured upstream of the weir plate at a 
minimum distance of 3 times maximum head to ensure the surface of the 
liquid is not affected by turbulence or drawdown. See Exponential devices, 
above, for further details. 
Palmer Bowlus and H-Flume Calculations 
Absolute 
If the flow calculation is to be absolute P702 = 1 the flow will be calculated 
using the formula: q = f(h)
 
Where:   
q = flowrate     
f  = is an 8
th
 degree polynomial solution for h (head)    
Ratiometric 
If the flow calculation is to be ratiometric P702 = 2 the flow will be 
calculated using the formula: q= q
cal 
f(h)/f(h
cal
) 
 Where:  
q = flowrate  
q 
cal 
= flowrate at maximum head P705   
f(h) = a polynomial solution for h (head)  
f(h
cal
) = a polynomial solution for h
cal 
(maximum head)