User`s guide

Theory of Thermal Desorption
302
Start of the Tube Conditioning Sequence—When the tube
conditioning sequence is started, the carrier gas pressure is tested,
the carousel moves to the first tube position and the system waits
until the system is ready. The first sample tube is then loaded into the
desorption position.
Leak Testing, Purging and Conditioning a Sample Tube—After
being placed in the desorption position, the tube is leak tested. When
the sample tube has passed the leak test, air is purged from the tube
to reduce the risk of adsorbent oxidation during conditioning. See
Carrier Gas Purge of the Sample Tube on page 310 for more details.
After the Leak Testing SV5 is opener, the sample tube is purged with
carrier gas for the duration of the purge time, which is set as part of
the method. After the purge time has elapsed, the tube oven is
brought into contact with the sample tube and the desorb time
begins.
Figure 87 Tube Conditioning
Transfer Line t
o GC
Sample
Tube
SV2
Carrier Supply
Carrier
Pressure
SV1
Desorb Supply
SV4
Outlet Split
SV5
Inlet Split
SV3
Desorb Vent
Leak
Pressure
Inlet Split/
Tube Condition Vent
A
Trap
Outlet Split
Vent
Desorb Flow
Vent
Pressure
Regulator
Supply
PR
Valve A
Position B
2
3
4
1