User Manual

3
Smart Infrastructure
CE2N5324en
2019-06-27
Technical design
Metering accuracy as per EN 1434
The diagram below shows the typical metering accuracy of the UH50.., compared to the
error limits per EN 1434, class 2.
-10
-
8
-6
-4
-2
0
2
4
6
8
10
1 10
100
Relative errors [%]
Flow [%/qp]
Error limit per EN 1434
Key:
EN 1434, class 3
EN 1434, class 2
UH50.. typical (EN 1434, ½ class 2)
The pressure loss in a flow sensor is indicated as nominal flow q
p
.
Actual pressure loss at the indicated flow can be calculated using the K
v
value, which
indicates flow at 1 bar differential pressure:
2
Δp = Pressure loss in bar
Q = Flow in m
3
/ h
K
v
= K
v
– Value at Δp = 1 bar
Nominal flow
q
p
m
3
/h
Mounting
length
mm
Connecting
thread
Pressure
loss at q
p
mbar
Kv value at
Δp = 1 bar
m
3
/h
Curve in the
diagram
0.6 110, 190 G ¾, G 1,
DN20
150 1.5 A
1.5 130, 190 G 1, DN20 160 3.8 B
1.5 110 G ¾ 150 3.9 C
2.5 190 G 1, DN20 210 5.3 D
2.5 130 G 1 200 5.6 E
3.5 260 G1¼, DN25 55 15 F