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6
Operating in CI Mode
To Set a Reagent Gas Flow
7000/7010 Series TQ GC/MS Operating Manual
141
To Set a Reagent Gas Flow
Procedure
1
In
Instrument Control
panel, select the
MS Tune
icon to display the
Triple
Quadrupole MS Tune
window. Select the
Manual Tune
tab, then select the
Ion Source
tab to display the ion source parameters.
2
In the
CI Reagent Gas Control
area, select
CI Gas A
if you are using methane
for the reagent gas or select
CI Gas B
to use the reagent gas attached to the
CI reagent gas controller’s B gas inlet for the reagent gas.
3
Enter the reagent gas flow setpoint in the
CI Gas Flow
field. This value is
entered as a percentage of maximum flow rate. The recommended flow is
20% for a PCI source and 40% for an NCI source.
4
Click
Set
. The
Flow Set
indication is displayed.
The reagent gas is flowing into the ion source at the rate displayed next to the
setpoint.
5
Click the
Files and Reports
tab, then click
Save
to save your changes to the
currently loaded tune file.
CAUTION
After the system has been switched from EI to CI mode, or vented for any other
reason, the MS must be baked out for at least 2 hours before tuning.
CAUTION
Continuing with CI autotune if the MS has an air leak or large amounts of water
will result in
severe
ion source contamination. If this happens, you will need to
vent the MS
and
clean the ion source
.