Agilent Technologies 6850 Series II User Information page 129

5.
6.
7.
8.
9.
10. Set the total flow to 60 mL/min. Wait a few moments for the pressure and
11. Turn either the pressure or the flow Off. Because the septum purge and
12. Monitor pressure on the Control Module or ChemStation/Cerity Chemical
13. When the system is leak-free, restore normal connections and operating
Released: March 2004
Cap the septum purge fitting with a 1/8-inch Swagelok cap or with a capillary
column nut, a solid piece of wire (such as a metal paper clip), and a 0.5 mm id
graphite ferrule.
Split vent
Septum vent
Set the oven and inlet to their normal operating temperatures.
Set the inlet to Split Mode.
Configure the column as 0 m length.
Make sure that the pressure at the gas supply is at least 35 psi. Enter a
pressure setpoint between 20 and 25 psi, or enter your normal operating
pressure if it is greater.
flow to equilibrate. If the GC cannot reach the setpoint, there is a large
leak somewhere. See
the column fittings are capped, gas is trapped in the system and the
pressure should remain fairly constant.
for 10 minutes.
• A pressure drop of 0.5 psi or less (approximately 0.05 psi/min) is
acceptable
• If the drop is greater than 0.5 psi, there is a leak that must be found
and corrected. See
• If the pressure rises, there is probably a leak in the in the flow
manifold across the forward pressure proportional valve. Although a
slight leak here does not cause a chromatographic problem, it may
obscure other small leaks that let air get into the system. The forward
valve can leak at 0.2 mL/min and be within specifications.
conditions.
6850 Series II GC User Information
"Correcting leaks" on page
"Correcting leaks" on page
Routine Maintenance: Inlets
Maintaining a split/splitless inlet
130.
130.
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