Agilent Technologies 5975C TAD VL MSD Troubleshooting And Maintenance Manual page 65

3
CI Troubleshooting
Poor vacuum without reagent gas flow
Excess water in the background
Scan from 10 to 40 m/z. A large peak at m/z 19 (>m/z 17) indicates water in the
background. If water is present, allow the instrument to bake out more and
flow reagent gas through the lines to purge any accumulated water.
Air leak
Run Methane Pretune. See the Operation Manual. A visible peak at m/z 32
indicates air in the system. Check for and correct any leaks. See the Leaks
section at the beginning of this chapter.
The foreline pump is not working properly
For the standard foreline pump, replace the pump oil. If that does not help, or
for the dry foreline pump, it may be necessary to replace the pump. Contact
your local Agilent Technologies Customer Engineer.
The turbo pump is not working properly
Check the pump speed. It should be at least 95%. Contact your local Agilent
Technologies service representative.
Use of ammonia as reagent gas can shorten the life of the foreline pump oil (with
CA UT IO N
standard pump) and possibly of the foreline pump itself. See "To Minimize Foreline
Pump Damage from Ammonia (Standard Pump)" on page 166.
5975 Series MSD Troubleshooting and Maintenance Manual 65