Analyzer Heaters And Radiators - HP 5973 Hardware Manual

Analyzer heaters and radiators

The ion source and mass filter are housed in cylindrical aluminum tubes called
radiators. The radiators control the distribution of heat in the analyzer. They also
provide electrical shielding for analyzer components. The source heater and tem-
perature sensor are mounted in the source heater block. The mass filter (quad)
heater and temperature sensor are mounted on the mass filter radiator. Analyzer
temperatures can be set and monitored from the MSD ChemStation.
In selecting the temperatures to use, consider the following:
• Higher temperatures help keep the analyzer clean longer.
• Higher ion source temperatures result in more fragmentation and therefore
lower high-mass sensitivity.
After pumpdown, it takes at least 2 hours for the analyzer to reach thermal equilib-
rium. Data acquired sooner may not be reproducible.
Recommended settings (for EI operation):
• Ion source 230°C
• Quadrupole 150°C
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Do not exceed 200°C on the quadrupole or 250°C on the ion source.
The GC/MSD interface, ion source, and mass filter (quad) heated zones interact.
The analyzer heaters may not be able to accurately control temperatures if the set-
point for one zone is much lower than that of an adjacent zone.
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