Agilent Technologies 5977B Series Operating Manual page 115

Never open the vent valve without first closing the hydrogen supply line to all
WA R N I N G
possible sources of hydrogen entry to the analyzer. This requires closing the
hydrogen shutoff valve to the carrier gas flow module and the shutoff valve to the
JetClean system supply if either of these hydrogen sources exist on the instrument.
7 Close shutoff valves to hydrogen sources that enter the analyzer if the
8 When prompted, turn the vent valve knob counterclockwise only 3/4 turns
Vent valve knob
Figure 38
5977B Series MSD Operating Manual
instrument is so equipped.
or until you hear the hissing sound of air flowing into the analyzer chamber.
(See Figure 38.)
Vent valve knob
Do not turn the knob too far, or the O-ring may fall out of its groove.
Operating in EI Mode 4
115