SRS Labs QMS 100 Series, User Manual

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SRS QMS Gas Analyzer Technical Reference
Chapter 2.
Quadrupole Spectrometer
This chapter describes the design and principles of operation of the components of the RGA quadrupole
probe.
In This Chapter
Introduction .......................................................................................................................................................................2-2
ECU......................................................................................................................................................................................2-3
RS232/DCE/28.8k Connector.....................................................................................................................................2-3
Calibration Lockout....................................................................................................................................................2-3
Electrometer........................................................................................................................................................................2-5
Detection limit vs. scan rate......................................................................................................................................2-5
Adjusting the Zero of the Ion Detector ..................................................................................................................2-6
Mass Filter Power Supply ................................................................................................................................................2-7
Ionizer..................................................................................................................................................................................2-8
Description ..................................................................................................................................................................2-8
Principle of operation.................................................................................................................................................2-9
Parameter Settings....................................................................................................................................................2-10
Quadrupole mass filter....................................................................................................................................................2-12
Description ................................................................................................................................................................2-12
Principle of operation...............................................................................................................................................2-13
Mass Range, Resolution and Throughput ...........................................................................................................2-14
Zero Blast Suppression ...........................................................................................................................................2-16
Ion Detector .....................................................................................................................................................................2-17
Description ................................................................................................................................................................2-17
Faraday Cup operation ............................................................................................................................................2-18
Electron Multiplier Operation .................................................................................................................................2-18