PerkinElmer CLARUS 590 GC, User Manual

Page: 82 / 284

82 . Clarus 590 GC User’s Guide
Now you can only pressure program your capillary injector. If you wish to program the Capillary
control for more than just pressure skip to step 9.
4. Under
Flow Offset
, select either the
Auto
or
Fixed
.
The Auto mode is the preferred mode of operation. If you want to shorten the overall run time at
the expense of some area precision, then use the Fixed mode.
We recommend that if you are operating with a split vent flow of 50 mL/min or less, select the
Auto mode.
Before each injection in the
Auto
mode, the system briefly closes the split vent and measures the
total flow. With the split vent off this flow is the column flow plus the septum purge flow. The
septum purge flow is maintained due to a mechanical restrictor and the split vent flow and split
ratio are maintained for each injection.
In the
Fixed mode, you enter an offset value which is equal to the septum purge flow plus the
column flow at the time of injection. Since the system controls the total flow (equal to the split
vent plus septum purge plus column flow), the septum purge is fixed, and the column flow is
controlled, the difference between these two flows and the offset entered will go out the vent flow.
This will be consistent for each run.
5. If
Fixed
is selected use the up and down arrow or keypad buttons to enter an offset
value in mL/min.
6. Press OK .