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Operating in EI Mode
94
5975/5977 Series MSD Operating Manual
Before You Turn On the MSD
Verify the following
before
you turn on or attempt to operate the MSD.
•
The vent valve must be closed (the knob turned all the way clockwise).
•
All other vacuum seals and fittings must be in place and fastened correctly.
The front side plate screw should not be tightened, unless hazardous carrier
or reagent gases are being used.
•
The MSD is connected to a grounded power source.
•
The GC/MSD interface extends into the GC oven.
•
A conditioned capillary column is installed in the GC inlet and in the GC/MSD
interface.
•
The GC is on, but the heated zones for the GC/MSD interface, the GC inlet,
and the oven are off.
•
Carrier gas of at least 99.9995% purity is plumbed to the GC with the
recommended traps.
•
If hydrogen is used as carrier gas, carrier gas flow must be off and the front
sideplate thumbscrew must be loosely fastened.
•
The foreline pump exhaust is properly vented.
WARNING
The exhaust from the foreline pump contains solvents and the chemicals you
are analyzing. If using the standard foreline pump, it also contains traces of
pump oil. If you are using toxic solvents or analyzing toxic chemicals, remove
the oil trap/mist filter (standard pump) and install a hose (11-mm id) to take
the foreline pump exhaust outside or to a fume (exhaust) hood. Be sure to
comply with local regulations. The oil trap supplied with the standard pump
stops only pump oil. It does not trap or filter out toxic chemicals.
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.