INFICON Explorer Portable Gas Chromatograph - Manual (Page 202)

Method Development
200
Integration Method
Normally, you do not need to alter the integration parameters. Setting these
parameters can require some expertise. You will need to perform a few runs to
ensure accurate integration. You may be able to obtain better integration by
smoothing the signal:
1. Press Enter Menu, DISPLAY, GC, GRAPH AND SMOOTH.
The signal will be smoothed.
2. Press SMOOTH again to further smooth the signal.
3. Press REINT, to re-integrate the chromatogram.
If you cannot obtain accurate integration using the preset integration parameters,
then you will have to modify the existing parameters.
The integrator extracts information from the detector signal. The integrator has been
designed to reduce or eliminate the user input required for good chromatographic
integration.
Chromatographic peaks are identified according to the following recognition
sequence based on the slope of the signal coming from the detector. The integrator
looks for each step to occur in sequence.
1. When the slope exceeds a threshold value for a certain time period, the peak
has started.
2. The slope goes negative for a time period.
This indicates the peak maximum has been detected.
3. At this point the height of the peak can be calculated.
If it is greater than the Minimum height value in the Integration Method then
the sequence is continued, otherwise the peak is disregarded and the integrator
goes back to step 1.
4. The slope, now negative, rises above a threshold value for a certain time
period. The end of the peak has been detected.