Milltronics OCM II PL-269, Инструкция по эксплуатации

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EXAMPLE 4: UNIVERSAL HEAD vs. FLOW CALCULATION
This example considers a type QV 306 Flume having a head-flowrate relationship as indicated by the graph
below. You wish to have 50 L/S as full scale. Since 25 cm will give 51.18 L/S we will use this as a start point. We
then divide the head measurements into 11breakpoints of 10 equal increments and extract the flow readings as
listed in the chart. If greater accuracy is required then the head can be divided into a maximum of 30 increments.
Breakpoint Head (cm) Flowrate (L/S)
0 0.0 0.00
1 2.5 1.47
2 5.0 4.12
3 7.5 7.94
4 10.0 12.24
5 12.5 18.24
6 15.0 23.35
7 17.5 30.00
8 20.0 36.47
9 22.5 43.83
10 25.0 51.18
You also want the totalization in cubic metres, output 4-20mA, all dimensions in cm, and you do not want the
output to change if there is a fault such as a cut transducer cable.
91/02/14
Flowrate (Litres / Sec.)
50
5.0
A
1
head
(cm)
A
2
A
6
A
0
(A
N
in this case)
A
7
30
20
10
40
A
8
A
9
A
10
A
4
A
3
A
5
7.5
10.0
12.5
15.0
17.5
20.0
22.5
25.0
2.5
0
X = The Head at which the OCM II output of 20 mA is desired.
( Eq
ual I
n
cre
m
ent
s
)
PL-269 9 – 6