User`s guide

Theory of Thermal Desorption
300
Figure 86 Standby Configuration
NOTE: SV is a solenoid valve, and PR is a pressure regulator in
this section.
In standby, flow is maintained through the GC column, and no tube
has been loaded. SV1 is closed. The column head pressure may be
adjusted by the pressure regulator to provide the required gas flow
through the column. SV2 enables carrier gas to be supplied to the
column in the gas chromatograph via the heated transfer line. The
heated valve is in Position B. This isolates the trap from the
atmosphere and prevents the flow of gas through the trap when the
system is idle.
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