Instructions for Use SS 20.261
Page 14
Analog outputs
Error signaling
If a critical operating condition occurs or if the sensor detects a
defect, one or both interfaces emit 2 mA
7
.
Representation of the measuring range
The measuring range of the corresponding measuring value is
mapped in a linear way to the signaling range of its analog output.
For flow measurement the measuring range reaches from zero to the
selectable end of the measuring range w
N,max
(= 100 % in Figure 5).
A higher flow up to 22 mA (= 112,5 %) is still output in a linear way,
moreover the signal remains constant.
Flow velocity w
N
Medium temperature T
M
0
112,5
w
N
[%]
0
20
40
80
60
100
I
Out
[mA]
20
4
22
12
8
16
I
Out
[m A]
0
90
-40
T
M
[°C]
20
4
8
20
22
40
+ 85
60
-20
12
12
16
2
)
4
(
16
,
max
,
mA
I
mA
w
w
wN
Out
N
N
C
mA
I
mA
C
T
wN
Out
M
20
)
4
(
16
105
,
Figure 6 Representation specification for measuring functions
The measuring range of the medium temperature is -20 to +85 °C.
Falling below this temperature causes the emission of an error
message of this signal output (2 mA). An exceeded temperature is
output in a linear way up to 90 °C, moreover the temperature output
leaps to approx. 22 mA and the flow output drops to 2 mA.
!
Even short-term overshooting of the operating medium
temperature can cause irreversible damage of the sensor.
!
For a correct temperature measurement, the flow velocity
on the sensor head must be > 2 m/s. An excessive
temperature value is output if flow velocity is < 2 m/s.
7
In accordance with NAMUR specification.