K-Patents PR-33-S - Manual (Page 25)

5 Configuration and calibration 21
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5 Configuration and calibration
5.1 Configuring the refractometer
In PR-33, all parameter changes are made with a web browser through the parameters
page, see Section 2.4.2.
5.1.1 Signal damping
The system provides the possibility to enter signal damping to diminish the influence of
process noise. The damping is applied to the CONC value (and thus the output signal).
The PR-33 offers two types of signal damping. Exponential (standard) damping works
for most processes and is the standard choice for slow and continuous processes. How-
ever, if the process has fast step changes, linear (fast) damping gives shorter settling
time.
The damping time is set separately. What the damping time means in practice, depends
on the damping type:
In the exponential damping, the damping time is the time it takes for the concentra-
tion 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 sensor to display concentration 55 %. A damping time of 5–15 seconds seems
to work best in most cases.
In the linear damping (fast damping), the output is the average of the signal during
damping time. After a step change the signal rises linearly and reaches the final value
after the damping time. Figure 5.1 shows how the damping time affects the measure-
ment.
Note: The factory setting for damping in PR-33-S is 5 s linear. Avoid overdamping, the
signal should not be made insensitive.