Pulsar FlowCERT LITE, Instruction Manual

Page: 61 / 150

Page
53
BS3680 Rectangular Broad Crested Weir
Point of Measurement
The transducer must be above the maximum head P704 by at least the near
blanking distance P107 .
The head is measured at a point 3 to 4 times the maximum head upstream
from the weir crest, to ensure the surface of the liquid is not affected by
turbulence or drawdown.
Calculations
A
BSOLUTE
If the flow calculation is to be absolute P702 = 1 the flow will be calculated
using the formula: q = (2/3)
1.5
C
e
b(gh
3
)
0.5
Where: q = flowrate
Ce = discharge coefficient calculated by FlowCERT
LITE
P723
b = approach width P710
g = gravitational acceleration (nominal value = 980.66 cm/s
2
)
h = head