Poor Vacuum Without Reagent Gas Flow - HP 5973 MSD Hardware Manual

Poor vacuum without reagent gas flow

Possible Cause
Excess water in the background.
Action
Scan from 10 – 40 amu. 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.
Possible Cause Air leak.
Action
Run Methane Pre-tune. See page 54. 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.
Possible Cause
The foreline pump is not working properly.
Action
Replace the pump oil. If that does not help, it may be necessary to replace the pump.
Contact your local Hewlett-Packard Customer Engineer.
Possible Cause The turbo pump is not working properly.
Action
Check the pump speed. It should be at least 95%. Contact your local Hewlett-
Packard service representative
& $ 8 7 , 2 1
Use of ammonia as reagent gas can shorten the life of the foreline pump oil and possibly
of the foreline pump itself. See the Maintenance chapter in this manual.
 Troubleshooting
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