Metrohm 761 Compact IC - Manual (Page 115)

4.4 Methods
761 Compact IC
105
Filters
Tab Filters of Method setup window with parameters for noise filtration of
raw data. Three different filtration algorithms are available to reduce
noise and increase apparent signal-to-noise ratio.
Spikes Spikes filter. The Spikes filter smoothes the
first and last points of the chromatogram and
the points identified as spikes. The spike is ex-
changed with half of the sum of two neighbor-
ing signal values.
Slit Median Median filter. Performs filtration if non-zero
smoothing degree is entered. Smoothing de-
gree should be a natural number. In the Median
filter the values within the window are sorted by
increasing response level and the response
corresponding to the middle of the window is
replaced with the value in the middle of a
sorted array. This method affects chroma-
tographic peaks in minimal extent, improves
baseline and very effectively eliminates single-
point spikes. In this case spike will be replaced
with one of the neighboring points.
Slit Gaussian Gauss filter. Performs filtration in non-zero
smoothing degree is entered. In case of the
Gauss filter the sum of all points within a win-
dow with Gauss weights distribution is calcu-
lated and used as a new raw data value. Peaks
after smoothing become a bit smaller and
wider, but their area does not change.
Raw data points Number of data points per chromatogram
(read-only).
Smallest peak has ... Number of data points per smallest peak on the
chromatogram (read-only). This information is
valuable to perform the Compress procedure
(data compression).