User`s guide

Method Development
217
required split ratio and then set the inlet split and outlet split flows
rates accordingly.
Carrier gas flow rates may be increased to enhance the process of
desorption from the tube and trap, and to facilitate transfer to the
cold trap during tube desorption. The option of using higher flow
rates to speed desorption is particularly useful during the analysis of
labile components when high temperatures cannot be used.
Pneumatics Tab
The Pneumatics tab provides information on the pneumatic settings
of the ATD/TD system. The ATD/TD pneumatics are not
programmable.
The TD pressure and various flows are manually adjusted with a
pressure regulator (main head pressure) and the respective needle
valves (Desorb Flow, Inlet Split Flow, Outlet Split Flow).
Therefore, the information displayed on this tab is for information
purposes only.
Pressure: The only pressure that should be set is the Column
pressure, required by the GC column for proper analytical
conditions.
It is manually adjusted, while monitored on the Column field in the
Status/Pnu tab; you only need to check the Show Actual box.
When finished, you must deselect the Show Actual and manually
enter the pressure value in the Column field. This entry has no
automatic function. It serves only notation purposes.
Flows: The three main flows are the Desorb Flow, The Inlet Split
Flow and the Outlet Split Flow.
The Internal Standard Addition Accessory will introduce two
more flows, the Loop Load Flow Rate and the Tube Load Flow
Rate.
All flows are manually adjusted, one at a time, by their respective
needle valves, while the flow is monitored by a suitable flowmeter
connected to the respective vent outlet.