Varian 450-GC, User Manual

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1079 PTV Injector - Injectors
Varian, Inc. User Manual 450-GC Page: 189
Manual Pneumatics
Tools and equipment needed
•
Bubble or electronic flowmeter, e.g., Varian Intelligent Digital Flowmeter, 01-
900115-00.
1. Turn the 1079 PTV Split Flow Controller (on the GC pneumatics panel)
counterclockwise to open the split flow controller.
2. Adjust the Back Pressure Regulator (on the GC pneumatics panel) to
establish a positive column head pressure (monitored on the pressure
gauge).
Set the column head pressure based on the column installed in the GC.
For example, for a 30m x 250 µm ID colu mn, set t he colu mn head
pressur e to 12-15 psi g to achi eve 1 mL/min col umn flow rate at 50 °C
oven temperatur e (helium ).
3. Connect the flowmeter to the split vent on the left side of the GC and
measure the split vent flow rate. Turn the Split Flow Controller valve to
adjust the split vent flow rate to 50 mL/min.
4. Adjust the Septum Purge Needle valve to adjust the septum purge flow rate
to 3-5 mL/min. Readjust the split vent flow rate to 50 mL/min.
5. Before heating the column, purge the system with carrier gas for 10 - 15
minutes.