Replacing The Heater/Sensor Assemblies - Agilent Technologies 6890 Series Service Manual

350 Flame Photometric Detector (FPD)
Replacement procedures

Replacing the heater/sensor assemblies

1. Turn off power to the gas chromatograph and disconnect the main power
cord. Remove the detector covers.
WARNING Always turn off power to the gas chromatograph and allow the heated zones
to cool. Unplug the power cord.
2. Allow time for heated zones to cool to safe temperatures.
Caution Always turn the electrometer or the main power off before removing the PMT
housing to avoid destroying the tube.
3. Pull the PMT housing off the detector module and remove the filter from
the detector. Set both in a safe place. Keep the open end of the PMT
covered whenever practical to avoid light damage to the tube.
4. Remove the exhaust tubing.
5. Remove the sheet metal cover. On the single wavelength detector, it is
held by two screws at the top and two at the bottom, while on the dual
wavelength detector it is held by two screws at the top.
6. If replacing the upper (FRONT) heater/sensor, remove it from the
detector module. Install a new heater/sensor. If not replacing the AUX1
heater, reassemble in reverse order.
20 of 36
Detectors
Agilent 6890 Gas Chromatograph Service Manual
Jun 2001