Agilent Technologies 7000 Triple Quadrupole GC/MS, Maintenance Manual

Page: 163 / 214

Analyzers and Collision Cell
7
Troubleshooting and Maintenance Manual 163
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) heaters and temperature sensors are mounted on
the mass filter radiators. Analyzer temperatures can be set and monitored
from the MassHunter Workstation software.
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
• Quadrupoles (front and rear)150
°
C
The GC/MS interface, ion source, and front 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.