E-m-pf4-v1_00 – ROTRONIC PF4 User Manual
Page 10
E-M-PF4-V1_00
Rotronic AG
Bassersdorf, Switzerland
Document Code
Unit
PF4 Differential Pressure Transmitter:
Instruction Manual
Instruction Manual
Document Type
Page 10 of 54
Document Title
© 2014; Rotronic AG
E-M-PF4-V1_00
3.2.3
Filters
The curve of the differential pressure measured values can be smoothened with the help of a low-pass filter
with selectable time constant. There are 13 smoothing filter stages available. Practice has shown stages 0...7
meet most application requirements.
Filter Stage
Time Constant
63
Time Constant
99
Description
0
0 s
0 s
No filtering
1
0.4 s
1.8 s
Weak filtering
2
0.9 s
4.3 s
…
3
1.9 s
9.3 s
…
4
3.9 s
19.3 s
…
5
7.8 s
39.2 s
…
6
15.8 s
78.9 s
…
7
32.0 s
2.7 min.
…
8
1.0 min.
5.3 min. Strong
filtering
9
2.1 min.
10.6 min.
…
10
4.2 min.
21.2 min.
…
11
8.5 min.
42.4 min.
…
12
17.0 min.
1.4 h
…
13
33.9 min.
2.8 h
Extremely strong filtering
3.2.4
Simulator Value
When the simulator value has been activated, a defined simulator value is used instead of the current measured
value.