Varian 4000 GCMS, Руководство по установке

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4.2 External Auto Tuning
EXTERNAL EI, PCI, and NCI
Ensure the GC column is delivering approximately 1 mL/minute of helium flow
into the ion source, the Trap Damping Gas Flow is delivering approximately 1
mL/minute helium flow into the trap cavity, and the Getter temperature is near its
set point.
1. From the Auto Tune page in System Control, click the Select All button, then
click the Start Auto Tune button. Allow the auto tunes to run to completion.
If the external CI option is installed continue to steps 2, 3, and 4. If the
external CI option is not installed, skip steps 2 and 3 and go directly to step
4.
2. Ensure a 25 psi supply of high purity (at least 99.95%) methane is delivered
through the 4 mL gaseous CI restrictor (03-930597-01) to the CI inlet port at
the back of the 4000 MS (refer to the installation instructions included with
the CI option for details). Turn the CI needle valve CCW until it stops. From
the Manual Control page, Checks and Adjustments tab, highlight CI Gas
Adjustment, select Methane as the Reagent, and click Start. Turn the CI
needle valve CW to increase CI flow into the analyzer until the Ion Gauge
Pressure reads approximately 50 to 60 uTorr. (The number of needle valve
turns required is typically about 6 turns.) Allow time for the CI reagent flow to
equilibrate while adjusting. Click Done when the adjustment is complete.
Figure 8.1 shows properly adjusted methane.
3. Return to the Auto Tune page in System Control, check only the Electron
Lens Tuning and Turn on CI gas flow during tune check-boxes, and click
Start Auto Tune (refer to figure 4.2). Allow this CI auto tune to run to
completion.
4. From the Manual Control page, Module Attributes tab, select the alternate
external filament (likely Filament 2) and return to step 1. Auto tune the
system using the alternate external filament including steps 2 and 3 if the CI
option is installed.
Figure 4.2