General Troubleshooting 2
Troubleshooting and Maintenance Manual 37
Foreline pressure is too low
If the pressures you observe are below 20 mTorr, check for the following:
• Column (carrier gas) flow is too low
• Column plugged or crushed by an overtightened nut
• Collision gas flows are too low
• Empty or insufficient carrier gas supply*
• Bent or pinched carrier gas tubing*
• Foreline gauge is not working correctly
* This could create a fault condition in the GC that would prevent the GC
from operating.
Quad pressure is too low
If the pressure you observe is below 1 × 10
-6
Torr with the collision cell gas on
or off, check for the following:
• Column (carrier gas) flow is too low
• Collision gas flows are too low
• Column plugged or crushed by overtightened nut
• Empty or insufficient carrier gas supply*
• Bent or pinched carrier gas tubing*
* This could create a fault condition in the GC that would prevent the GC
from operating.