7
Diagnostics and Troubleshooting
Troubleshooting
Thermo Scientific TSQ Quantum XLS Series User Guide 125
Issue: The
chromatogram has a low
total ion current signal.
Possible causes/solutions
• The GC temperature ramp does not continue to a high enough temperature to elute high
boiling point compounds. Multiple injections cause these compounds to accumulate in a
column, reducing sensitivity. Extend upper temperature or the time at upper temperature
in the GC oven ramp.
• The instrument is out of tune, or the tune file is incorrect. Select the correct tune file for
the method or run automatic tune as described in “Running Auto Tune and Calibration”
on page 64.
• The ion volume is contaminated. Clean the ion volume.
• The ion volume is incorrectly positioned. Position the ion volume properly.
• The magnets above and below the ion source are installed incorrectly. Position both
magnets so that the south pole is on top. Electrons will not focus into the ion volume if
one magnet is upside down.
• Dust has collected in the electron multiplier or on the conversion dynode. Contact
Thermo Fisher Scientific Technical Support.
• The emission current is set too low. Check the setting listed for the emission current.
• The ground connection between the Electrometer PCB and anode feedthrough is faulty.
Contact Thermo Fisher Scientific Technical Support.
•There is a problem with the filament or lens control. See “Filament and Lens Control
Issues” on page 119 for more information.
• The EI/CI Source PCB is faulty, which allows emission current to leak to ground.
Contact Thermo Fisher Scientific Technical Support.
• Reagent gas is leaking into the analyzer and suppressing EI signal. Check for presence of
CI reagent ions in the spectrum. Replace CI Gas Flow Module if necessary.
To Next Page
Loading...
Need help?
General
