Agilent Technologies 5975T LTM GC/MSD, Troubleshooting And Maintenance Manual

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212 Troubleshooting and Maintenance Guide
13
Analyzer
Analyzer Heaters and Radiators
The ion source and mass filter are housed in cylindrical
aluminum tubes called radiators (
Figure 34 ). The radiators
control the distribution of heat in the analyzer. They also
provide electrical shielding for analyzer components. The
source heater and temperature 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 equilibrium. Data acquired sooner may not be
reproducible.
Recommended settings (for EI operation):
• Ion source 230

C
• Quadrupole 150

C
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 setpoint for one zone is
much lower than that of an adjacent zone.
C A U T I O N
Do not exceed 200 °C on the quadrupole or 350 °C on the ion source.