Replacing The Electrometer - Agilent Technologies 7820A Service Manual

54
Agilent 7820 GC Service
requested information.

Replacing the electrometer

1 Cool down the oven.
Turn off the GC main power switch and disconnect its power
cord.
Hazardous voltages are present in the
mainframe when the GC power cord is connected.
Avoid a potentially dangerous shock hazard by
disconnecting the power cord before removing
any GC panels.
Components can be damaged by static electricity:
be sure to wear an ESD strap grounded to the GC
chassis while performing this procedure.
Turn off all gas flows at their sources.
Inlets, detectors, and the oven are insulated
with fibrous materials which may cause
irritation to skin, eyes, and/or mucous
membranes. Always wear gloves when working
with the insulation.
insulation is flaky/crumbly, wear protective
eyewear and a suitable breathing mask and/or
respirator.
Remove the right side electronics cover.
Disconnect the electrometer ribbon cable from the FID signal
board.
Remove the Torx T-20 screw and clamp over the interconnect
tube.
Remove the two Torx T-20 screws from each end of the
electrometer.
Additionally, if the