INFICON Explorer Portable Gas Chromatograph - Manual (Page 275)

Explorer Operator Manual
273
Cause: Instrument is adapting to change of the PID sensitivity (gain switch).
Action: Increase the pump time to 20 seconds. After the gain is switched,
Explorer begins to stabilize the offset during the pump time.
Cause: Column is recovering from earlier contamination.
Action: Increase the pressure and flush the column, as detailed in Flushing
the Columns on page 250.
Cause: Components of the last analysis are still on the column.
Action: Purge the column as above, but decrease the backflush duration to flush out
the heavier compounds. If the heavier compounds must be detected, adjust the
analysis time so these compounds have enough time to clear the column. Also,
ensure you have selected the correct column for your application.
Cause: Contamination in the external carrier gas cylinder.
Action: Switch to an alternate carrier gas tank.
Cause: Contamination in the internal carrier gas cylinder.
Action: Purge the internal tank as outlined in Purging the Internal Carrier
Gas Cylinder on page
253.
NOTE: To prevent contamination from entering Explorer's pneumatic system, do not allow
the internal tank to empty completely.
Cause: Peaks are appearing from the previous analysis.
Action: Decrease the foreflush time or increase the analysis time.