Siemens OCM III, Instruction Manual, Page: 57 / 112

BS-3680 Rectangular Flume, P3 = 1
‘U’ parameters required * ‘U’ parameters calculated **
U0 = approach width B U4 = Cv
U1 = throat width b U5 = Cd
U2 = hump height p U6 = A
U3 = throat length L
*obtain from manufacturer’s specifications.
**
calculated by OCM-3. May be viewed by accessing ‘U’ parameter.
Reference
ABSOLUTE CALCULATION, P4 = 0
¤
For flows that can be calculated by the equation:
q = (2/3)
1.5
x g
0.5
x Cv x Cs x Cd x B x h
1.5
where : q = flow rate Cv = velocity coefficient
b = throat width Cs = shape coefficient
g = gravitational acceleration Cd = discharge coefficient
h = head
RATIOMETRIC CALCULATION, P4 = 1
¤
For flows that can be calculated by the equation:
q = q
cal
x Cd/Cd
cal
x Cv/Cv
cal
x (h/h
cal
)
1.5
where : q = flow rate
q
cal
= flow rate at maximum head
h = head
h
cal
= maximum head
Cv = velocity coefficient
Cv
cal
= velocity coefficient for maximum head
Cd = discharge coefficient for head
Cd
cal
= discharge coefficient for maximum head
¤
Refer to Operation \ Flow Calculation.
7ML19985AB01 OCM III 58