Setting Up A Median Filter; Setting Up A Damping Period - ABB LWT300 series User Manual

Setting up a median filter

The median filter is designed to filter out noisy measurement spikes in applications with fast transients
(e.g., rapidly varying processes, positioning applications, etc). It is used for discarding occasional false
measurements resulting from any occasional unwanted phenomena that might occur in the process.
The value entered corresponds to the number of measurements kept in the buffer. The filter then
generates and returns a median value of all the measurements kept in the buffer. The buffer size can
range from 1 to 50 measurements. The default value is 1.
NOTICE
Selecting 1 measurement effectively disables the median filter as no averaging can be
performed.
To set a median filter:
1 Select Device Setup > Filtering > Median Filter.
2 Press Edit.
3 Set the number of measurements that you want kept in the filter buffer (between 1 and 50) and
press OK.

Setting up a damping period

The instrument damping filter is designed to smooth out measurement noise in applications with slow
dynamics (e.g., liquids with slow waves).
The damping value corresponds to the time constant (ranging from 1.0 to 99.9 s) applied to the
measurement returned by the median filter. The default value is 0.0 s (no damping is applied).
To set a damping period:
1 Select Device Setup > Filtering > Damping.
2 Press Edit.
3 Set the damping period and press OK.
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User Guide