User guide

226 Advanced User Guide
8 Inlets
About the PTV Inlet
The Agilent Programmed Temperature Vaporization (PTV) Inlet
System has five operating modes:
• The split mode is generally used for major component
analyses.
• The pulsed split mode is like the split mode, but with a
pressure pulse applied to the inlet during sample
introduction to speed the transfer of material to the column.
• The splitless mode is used for trace analyses.
• The pulsed splitless mode allows for a pressure pulse during
sample introduction.
• The solvent vent mode is used for large volume injection.
Either single or multiple injections can be made for each run.
The PTV inlet can be used with both manual and automatic
injection.
For automatic multiple injections (large volume injections), an
Agilent GC or MSD ChemStation is required. This function is
not available under GC control alone. See “PTV inlet solvent
vent mode” on page 239.
PTV sampling heads
Two heads are available for the PTV inlet.
The septum head uses either a regular septum or a Merlin
Microseal™ to seal the syringe passage. A stream of gas sweeps
the inner side of the septum and exits through the septum purge
vent on the pneumatics module. It may be used with either
automatic or manual injection.
The septum head uses either standard 11 mm septa or (with a
different cap) a Merlin Microseal.
The septumless head uses a check valve instead of a septum to
seal the syringe entrance passage. It may be used with either
automatic or manual injection. This head is recommended for
subambient inlet operation.