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RATIOMETRIC 
BS3680 Rectangular Weir 
If the flow calculation is to be ratiometric P702 = 2 the flow will be 
calculated using the formula: q= q
cal
C
e
/C
ecal
(h
e
/h
ecal
)
1.5
 
Where:  q  =   flowrate        
q 
cal 
= flowrate at maximum head P705                              
Ce  = discharge coefficient calculated by FlowCERT LITE P723 
Ce
cal
  = discharge coefficient at maximum head      
he  = effective head       
he
cal
  = effective head at maximum head