Unstable Or Low-Intensity Ion Beam - Waters Xevo TQ-GC Overview And Maintenance Manual

Table 6–1: No ion beam
Possible causes
Improperly connected cables.
Communication failure.
Damaged filament.
Unsuitable tuning parameters.
No reference gas.
The vacuum is operating too poorly for the
filament to turn on.

6.2.2 Unstable or low-intensity ion beam

The following table lists the possible causes and corrective actions for this problem.
Table 6–2: Unstable or low-intensity ion beam
Possible causes
Setup of the GC, such as column cutting or
column position.
Adsorption of sample into column or injector;
dirty injector.
April 27, 2020, 715005564 Ver. 01 (previously released as Rev. A)
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Corrective action
If readbacks for emission current and filament
current are 0, ensure that all of the necessary
cables are correctly attached to the inner
source.
Reinitialize the instrument. In the Tune window,
click Acquire > Reinitialize. If a problem
persists, press the reset switch to reboot the
embedded PC (EPC).
If readbacks for emission current and filament
current are 0, remove the inner source and
verify continuity of the filament with a digital
voltmeter (approx. 0.2 ohm). If the filament is
damaged, replace it.
Verify the tuning parameter settings and their
readbacks.
Refill the reference gas ampule.
For corrective action, see
vacuum.
Corrective actions
Look for source pressure, quality of peak
separation, and tailing.
Inject OFN, which is retained in the column, to
determine whether the problem originates with
the GC. A leak in the GC can damage the
column or destroy the filament. Adjust the
column position.
Ensure that the GC parameter settings, such
as those for flow rate, purge time, purge flow,
and split ratio, are appropriate.
Clean the injector line.
Poor source