INFICON Explorer Portable Gas Chromatograph - Manual (Page 117)

Explorer Operator Manual
115
Other Features
Enter the concentration of the compound in the calibration gas.
This concentration should be close to the concentration to be detected.
Enter an alarm level.
If an alarm is exceeded an audible alarm may sound and an alarm
acknowledge box will be displayed. The audio options are selected on
Explorer itself, see Audio Options on page 67.
Enter the window percent.
The window percent is the deviation in retention time for which
Explorer will
compensate. For example, if the window is set at 10%, a compound with a
retention time of 100 seconds will still be identified if it elutes between 90 and
110 seconds. Most compounds have a 3 – 5% window.
Select how you want the peak identified: as the largest peak in the window or
as the closest retention time in the library.
If there are interference compounds, that appear at the same retention time, but
are not as responsive to the PID or are present in very low concentrations, then
select the largest peak in the window.
If the interference compound is close in detector response, but has a different
retention time, then select closest retention time.
Calibration Curve
Select the desired curve fit option. You must create the calibration curve by storing
the compound at multiple concentrations throughout the range of your application.
You can store up to 5 concentration points.
If it is not possible to store the compound at 5 concentrations, store the compound at
two concentrations within the range of your application to ensure the best results.
The concentration and the corresponding area are shown for all concentration points
that you have stored. See Multiple Point Calibration Curve on page
165 for details
of storing a compound at more than one concentration.