1Introduction
Vacuum gauge
7000/7010 Series TQ GC/MS Operating Manual 17
Vacuum gauge
The 7000/7010 Series TQ GC/MS is equipped with two ion vacuum gauges. The
Agilent MassHunter GC/MS Acquisition software can be used to read the
pressure (high vacuum) in the vacuum manifold and at the turbomolecular
vacuum pump discharge.
7000/7010 CI MS System
In this manual, the term “CI MS” refers to the 7000/7010 Series TQ GC/MS CI
source system. It also applies, unless otherwise specified, to the mass flow
controller (MFC) for these instruments.
The 7000/7010 Series TQ GC/MS CI source system (preconfigured or upgrade
kit) adds to the 7000/7010 TQ MS:
• EI/CI GC/MS interface
• CI source
• Reagent gas MFC system
• JetClean option available that shares the same MFC system
• HED with high sensitivity electronics
• Bipolar HED power supply for PCI and NCI operation
A required methane/isobutane gas purifier is provided. It removes oxygen, water,
hydrocarbons, and sulfur compounds.
The CI MS system has been optimized to achieve the relatively high source
pressure required for CI while still maintaining high vacuum in the CC,
quadrupoles, and detector. Special seals along the flow path of the reagent gas
and very small openings in the ion source keep the source gases in the ionization
volume long enough for the appropriate reactions to occur.
The CI interface has special plumbing for reagent gas. A spring-loaded insulating
seal fits onto the tip of the interface.
Switching back and forth between CI and EI sources takes about 1 hour,
however, a 1- to 2-hour wait is required to purge the reagent gas lines and bake
out water and other contaminants. Switching from PCI to NCI requires about
2 hours for the ion source to cool.
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