Varian 450-GC, User Manual

Page: 118 / 205

Injectors – 1079 PTV Injector
Page: 180 User Manual 450-GC Varian, Inc.
1079 Injector Screen
The 1079 Injector screen allows modifying the Injector parameters.
With the Enable checkbox it is possible to enable/disable the Injector
temperature control.
In the Temperature box the wanted Injector temperature can be set.
The Split State controls the flow of carrier gas through the Injector during the
analytical run. When the Split State is unchecked, most of the sample injected
is directed onto the column. When the Split State is checked, the sample is split
in the Injector with typically the smaller fraction entering the column and the
larger fraction being vented.
In the example below is a splitless injection. The Injector is held in the split state
for the initial period with split ratio of 20. When the run is started the split state
will switched Off. After 0.9 minute the split is switched on again.
The Coolant checkbox turns on or off the cryogenic supply to the Injector, if
installed. In the example below the cooling will start when the Injector
temperature reaches the 250 °C. In the
setup screen of the Injector tab 1079 some
rarely changed coolant parameters can be
changed, like coolant type (LN
2
, LCO
2
or Air)
and coolant timeout.
Coolant time-out refers to the period of time
for which the coolant will remain on after it is turned on. For example, if the set
temperature has not been reached or the run has not started within the
specified time, the coolant supply will be turned off.