320
Nitrogen Phosphorus Detector (NPD)
Replacement procedures
Replacing the jet
After removing the collector assembly, you can replace the jet. If
contamination is present in the detector, replacement of the jet is
recommended. However, the jet can be cleaned as described in the Cleaning
the jet procedure in this section.
WARNING
Before proceeding, turn off the oven and any heated zones and let them cool
down. Turn off any detector gases at their supply. Then turn off the main
power switch and unplug the power cord.
Caution
To avoid detector contamination, use clean lint-free gloves when handling the
internal detector components. The detector bead is fragile, avoid touching
the bead or letting it touch other surfaces.
1.
Remove the collector as described in the Removing the collector assembly
procedure.
2.
Use a 1/4-inch deep-socket nut driver to unscrew the jet.
3.
Use slight side pressure on the nut driver to drag the jet up out of the
detector weldment and then use tweezers to grasp and remove the jet.
18 of 32
Detectors
Agilent 6890 Gas Chromatograph Service Manual
Jun 2001