Installation manual

140 5975 Series MSD Operation Manual
6 CI Maintenance
General Information
Ion source cleaning
The main effect of operating the MSD in CI mode is the need for more frequent
ion source cleaning. In CI operation, the ion source chamber is subject to more
rapid contamination than in EI operation because of the higher source
pressures required for CI.
Ammonia
Ammonia, used as a reagent gas, increases the need for foreline pump
maintenance. Ammonia causes foreline pump oil to break down more quickly.
Therefore, the oil in the standard foreline vacuum pump must be checked and
replaced more frequently.
Always purge the MSD with methane after using ammonia.
Be sure to install the ammonia so the tank is in an upright position. This will
help prevent liquid ammonia from getting into the flow module.
WARNING
Always perform any maintenance procedures using hazardous solvents under a
fume hood. Be sure to operate the MSD in a well-ventilated room.