INFICON Explorer Portable Gas Chromatograph - Manual (Page 203)

Explorer Operator Manual
201
Peak retention times are measured when the slope changes from positive to negative
(the peak maxima).
Peak areas are calculated by summing the area slices beneath the signal and
subtracting the area below the line connecting the start and end points.
Up Slope, Down Slope and Filter
The slope of the signal is calculated from a five point moving average and is
compared with the effective up and down slope sensitivities to start and stop the
integrator.
Since baseline noise is constant throughout the chromatogram, the reduced slope
sensitivities may allow false noise peaks to be detected. To reduce these effects the
integrator filters the signal by averaging the signal over larger periods while
reducing the slope sensitivities. This allows the signal to noise ratio to remain
constant throughout an analysis giving good integration on both early and late peaks.
Filter 1 provides the most filtering with the signal being averaged over the longest
period before the slope is calculated. Filter 4 provides the most versatility; the signal
is analyzed simultaneously by four different filters as with auto-integration. When
the signal noise is low, select Filter 4. For noisier signals, select lower Filter
numbers.
To change the settings:
1. Press Enter Menu, SETUP, CONFIG, COLUMN.
2. Select the column for which you want to alter the integration settings. Disable
the other columns.
3. Press Exit to close the box. Press Enter Menu to close the menu.
4. Press Enter Menu, SETUP, CONFIG, METHOD, METH, and SLOPES.