K-Patents PR-21-S - Manual (Page 49)

6 Configuration and calibration 43
6 Configuration and calibration
All changes of configuration and calibration are made through the Calibration
menu selected from the Main menu by
5 CALIBRATION .
Password: It may be necessary to enter a password before proceeding to the Cali-
bration menu. The password is printed on the title page of this manual. The pass-
word function is activated and deactivated via the
6 PASSWORD command in the Cal-
ibration menu. By default the password is activated.
6.1 Configuring output signal damping
The Outputs display also provides the possibility to enter signal damping to di-
minish the influence of process noise. The damping is applied to the CONC value
(and thus the output signal) of the current sensor (see upper edge of the display
to check which sensor is currently chosen and switch in the Outputs display if nec-
essary).
The PR-21-S offers three types of signal damping. The damping parameter is set
separately through the Outputs menu selected from the Calibration menu by
2 OUT-
PUTS . What the damping time means in practice, depends on the damping type.
6.1.1 Exponential damping
Exponential (standard) damping works for most processes and is the standard
choice for slow and continuous processes. The factory setting is always expo-
nential damping, access the
3 DAMPING TYPE command to switch between different
damping algorithms. In the exponential damping (standard damping), the damp-
ing time is the time it takes for the concentration measurement to reach half of
its final value at a step change. For example, if the concentration changes from
50 % to 60 % and damping time is 10 s, it takes 10 seconds for the DTR to dis-
play concentration 55 %. A damping time of 5–15 seconds seems to work best in
most cases, the factory setting is 5 seconds. Use the
4 DAMPING TIME menu item to
set the damping time. Figure 6.1 shows how exponential damping time affects the
measurement.
0 10 20 30 40 50 60 70 80 90 100 110 120
Time [s]
12.0
12.1
12.2
12.3
12.4
12.5
12.6
12.7
12.8
12.9
13.0
CONC [%]
5 s
10 s
20 s
Figure 6.1 Exponential damping