User`s guide

Operation
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Heat Rate—Once the volatiles are transferred from the sample tube,
the trap is heated. Set the heating rate to any value between 5, 20, 40
and 99°C/second (ballistic). The faster heating rates ensures that
volatile compounds are transferred to the GC column in a narrow
band. Lower rates provide a slower heating for use in the analysis of
analytes that are thermally labile.
The trap is heated to the high temperature at the selected rate. This is
the secondary desorption step.
Heated Valve Temperature —The heated valve is a 4-port rotary
valve and is used to direct the carrier gas flow to the cold trap during
the desorption process, or to isolate the cold trap during tube
conditioning. The heated valve and its associated pneumatic
connections may be heated to between 150°C and 300°C using the
valve rotor supplied with the ATD/TD.
You can view the actual settings or the set points on this tab. The set
points are determined by the method that is currently active. The
method name is also displayed on the tab. If you are viewing the
actual settings, these values are from the instrument. When you are
viewing the actual temperatures, the parameters that have reached
their set points are displayed in black. Those that are still changing
are displayed in red.
The settings that you enter here are dependent on your application.
Refer to Chapter 5 for details on method development.
To set the temperature:
1. Press the Set-Points radio button. The current
temperature set-points will be displayed.
2. Press the desired entry box. The option will be
highlighted to indicate that it is active.
3. Press the + or – buttons to increase or decrease the
temperature to the desired value.
4. The ATD/TD will cool or heat the selected zone to the
new temperature. Allow a few minutes for the
instrument to reach the new value. You can switch to
actual to view the current instrument temperatures. The
new value will be displayed in red until it reaches the
new set point.