Spectrometer Tube Description - Agilent Technologies VS Series Operation Manual

A.1 Spectrometer Tube Description
The spectrometer tube is a heart of the VS Series Helium Mass Spectrometer Leak Detector
and is quantitatively sensitive to the presence of helium.
The VS Series spectrometer tube:
Creates positive ions from gas molecules that penetrate inside the spectrometer,
maintained under high vacuum, via any leaks in the unit under test (UUT), which is
connected to the test port
Separates helium from all other gas ions, detects helium and total gas pressures as
currents
Converts the helium current into voltage with amplification.
The VS Series leak detector spectrometer tube is a stand-alone unit comprised of five
sections:
Spectrometer tube body with magnets
Ion source with two filaments section
Electro-magnetic ion lenses
Electrometer section for the partial helium pressure signal
Collector plate for the total pressure signal
A-2
VS Series Component Leak Detector