Specifications

Analyzer 7
5975 Series MSD Troubleshooting and Maintenance Manual 213
Analyzer Heaters and Radiators
The ion source and mass filter are housed in cylindrical aluminum tubes
called radiators (Figure 49). 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.
CAUTION
Do not exceed 200 °C on the quadrupole or 350 °C on the ion source.