PULSAR MEASUREMENT
95
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.
Rectangular Broad Crested Weir Calculations
Calculations
Absolute
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 UltraTWIN
P723
b = approach width
P710
g = gravitational acceleration (nominal value = 980.66 cm/s
2
)
h = head
