ULTRATWIN (UL)
INSTRUCTION MANUAL
98
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)
V-Notch Angle Weir (Non-BS 3680) Calculations
Absolute
If the flow calculation is to be absolute P702 = 1 the flow will be calculated
using the formula: q = C
e
8/15 tan (theta/2)(2gn)
0.5
(h = kh)
2.5
Where: q = flowrate
C
e
= discharge coefficient calculated by UltraTWIN (P723)
theta = V-notch angle
gn = gravitational acceleration
h = head
kh = compensated head
Ratiometric
If the flow calculation is to be
ratiometric P702 = 2
the flow will be
calculated using the formula: q= q
cal
(h+kh/h
cal
+kh)
2.5
Where: q = flowrate
q
cal
=
flowrate at maximum head P705
h = head
kh = compensated head
