Pulsar UltraTWIN, Instruction Manual

Page: 87 / 214

PULSAR MEASUREMENT
87
Rectangular Flume 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
gn
0.5
C
s
C
v
C
d
bh
1.5
Where:
q = flowrate
gn = gravitational acceleration (nominal value = 980.66 cm/s
2 )
C
s
= shape coefficient (value = 1)
C
v
= velocity coefficient calculated by UltraTWIN (P721)
C
d
= discharge coefficient calculated by UltraTWIN (P722)
b = throat width P711
h = head
Ratiometric
If the flow calculation is to be ratiometric P702 = 2 the flow will be
calculated using the formula: q= q
cal
(C
v
/C
vcal
)(C
d
/C
dcal
)(h/h
cal
) 1.5
Where:
q = flowrate
q
cal
= flowrate at maximum head P705
C
v
= velocity coefficient calculated by UltraTWIN (P721)
C
vcal
= velocity coefficient at maximum head
C
d
= discharge coefficient calculated by UltraTWIN (P722)
C
dcal
= discharge coefficient at maximum head
h = head
h
cal
= maximum head P704