Operating in Electron Ionization (EI) Mode 3
5977 Series MSD Operation Manual 83
7 Once the MSD has pumped down, close the analyzer cover.
WARNING
The front thumbscrew must be fastened for CI operation or if hydrogen (or other
hazardous gas) is being used as the GC carrier gas. In the unlikely event of an
explosion, it may prevent the side plate from opening.
CAUTION
Do not overtighten the thumbscrew; it can cause air leaks or prevent successful
pumpdown. Do not use a screwdriver to tighten the thumbscrew.