Installation manual

Operating in Electron Impact (EI) Mode 3
5975 Series MSD Operation Manual 91
To pump down the MSD
You can also use the Local Control Panel to perform this task. See “Operating
the MSD from the LCP” .
Procedure
1 Close the vent valve.
2 Plug in the MSD power cord.
3 Open the MSD Analyzer top cover.
4 Turn on the MSD while engaging the side plate to the manifold using hand
pressure.
5 Press lightly on the side board to ensure a correct seal. Press on the metal
box on the side board.
The foreline pump will make a gurgling noise. This noise should stop within
a minute. If the noise continues, there is a large air leak in your system,
probably at the side plate seal, the interface column nut, or the vent valve.
6 Start the ChemStation and select Tune and Vacuum Control from the View
menu.
7 Select Pump Down from the Vacuum menu.
WARNING
Make sure your MSD meets all the conditions listed in the introduction to this
chapter (page 60) before starting up and pumping down the MSD. Failure to do so
can result in personal injury.
WARNING
If you are using hydrogen as a carrier gas, do not start carrier gas flow until the
MSD has been pumped down. If the vacuum pumps are off, hydrogen will
accumulate in the MSD and an explosion may occur. Read “Hydrogen Safety”
before operating the MSD with hydrogen carrier gas.
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