4
Operating in EI Mode
106
5975/5977 Series MSD Operating Manual
To Pump Down the MS
You can also use the 7890B GC control panel to perform this task. See
“Operating the MSD from the GC Control Panel”
Procedure
1
Remove the analyzer window cover (see
2
Close the MS vent valve by turning it clockwise.
.
3
Plug the MS power cord into a grounded electrical outlet.
4
Turn on the MS power switch.
5
Press lightly on the metal box of the analyzer quad driver board to ensure a
correct seal.
WARNING
Make sure your MSD meets all the conditions listed in the introduction to this
chapter (
) 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
on page 19 before operating the MSD with hydrogen carrier gas.
Figure 31.
Vent valve knob
Vent valve knob