Varian 4000 GC, Hardware Operation Manual

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6. On the back of the instrument, loosen the two screws that hold the plug in the
CI Shutoff Manifold 2 to 3 turns. Remove the plug by pulling straight out and
twisting.
7. Use the 4 mL/min restrictor tube for the supply line between the gas cylinder
and the CI shutoff manifold. No ferrule is required on the mass spectrometer
end of this tube. The seal is made with an elastomer O-ring.
8. Carefully insert the restrictor tube into the CI shutoff manifold hole (the one
the plug came out of) until it is firmly seated. Tighten the two screws.
9. Ensure that the secondary valve on the regulator on the gas cylinder is
closed.
10. Open the main control valve on the lecture bottle. Next, open the secondary
valve and adjust the pressure valve to approximately 20 psi.
11. Open the mass spectrometer door. Verify that the CI GAS needle valve is
turned fully counterclockwise.
12. Next, flush the gas line of air and water vapor by doing the following.
•
Monitor the foreline pressure on the diagnostics screen. Do not allow the
foreline pressure to exceed 500 mTorr for more than 20 seconds.
•
Turn the adjustment valve clockwise to reduce the pressure.
•
Open the CI Gas solenoid valves by clicking on the CI icon in the Control
and Status field of the Manual Control tab dialog in System Control.
When the valves are opened, the CI button is green.
•
Evacuate the CI reagent supply line for about 30 minutes.
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