Metrohm 761 Compact IC - Manual (Page 164)

4 Operation
761 Compact IC
154
Subtraction of a chromatogram
761 COMPACT IC / Process / More / Subtract
This menu item opens the Subtract chromatogram window allowing the
subtraction of any opened chromatogram from the active, selected
chromatogram.
Select the chromatogram that should be subtracted, click on <Sub-
tract> and then on 761 COMPACT IC / View / View all . The result is shown
in the active chromatogram window, which is considered as a new
chromatogram and will be stored under a new name to avoid overwrit-
ing of old data.
Data compression
761 COMPACT IC / Process / More / Compress
Selection of this menu item opens the Raw data compression window for
compression of the raw data of the active chromatogram by summing
up several neighboring points.
Divisor
Coefficient of compression (the number of data points is
reduced by this value). The default value of the compres-
sion coefficient is calculated so that the width at half-height
of the narrowest peak will be digitized by at least 30 points.
If the user enters a coefficient of compression that exceeds
the value offered by the software, integration precision may
decrease.
Invert chromatogram
761 COMPACT IC / Process / More / Invert!
This menu item inverts the response curves for all channels of the
chromatogram so that negative peaks become positive and vice versa
(useful for chromatograms with wrong input polarity).