Instructions for Use
– SCHMIDT
®
Flow Sensor SS 20.600
Page 29
Pulse outputs
The two pulse outputs provide the same measured variable, which de-
pends on the sensor configuration:
In standard configuration the sensor maps the flow velocity w
N
propor-
tional to a frequency range [0
… f
max
], with selectable maximum fre-
quency f
max
(see Figure 5-3).
Figure 5-3 Example for f
max
= 100 Hz
𝑓
𝑚𝑎𝑥
= 10 … 100 𝐻𝑧
max
,
max
N
w
f
f
N
w
max
,
max
N
V
f
f
N
V
N
V
: Standard volume flow
The volume flow
𝑉̇
𝑁
and the pulse valence V
N,Imp
(= volume per pulse)
can be determined on base of the actual output frequency, the measur-
ing range w
N,max
of the sensor and the inner pipe diameter D:
𝑉̇
𝑁
= 𝑤
𝑁
∙ 𝑃𝐹 ∙ 𝐴
𝐷
= 𝑤
𝑁
∙ 𝑃𝐹 ∙
𝜋
4
∙ 𝐷
2
;
𝑉
𝑁,𝐼𝑚𝑝
=
𝑉̇
𝑁,𝑚𝑎𝑥
𝑓
𝑚𝑎𝑥
When configured as a consumption meter, pulses with a predefined
pulse valency (e.g. 1 m³/pulse) are transmitted.
To do this, the inner pipe diameter D must be specified when ordering
(D
min
= 25 mm).
Exceeding the measuring range of the flow w
N
is also output linearly up to
110 % of the measuring range. The output of higher flow values is limited
to 110 % of the measuring range.
If an error occurs, 0 Hz or no pulses will be output. The current initial state
remains unchanged.
Note:
The relay can be used as
“S0-Interface” according to EN 62053-31
22
.
22
Former standard: DIN 43 864
f
Out
[Hz]
0
110
w
N
[%]
100
0
20
110
40
80
60
100
40
20
60
80
