To Maintain The Npd Collector, Ceramic Insulators, And Jet - Agilent Technologies Agilent 7890 Series Maintenance Manual

To Maintain the NPD Collector, Ceramic Insulators, and Jet

C A U T I O N
WA R N I N G
Maintaining Your GC
When replacing the jet, always install a new collector,
ceramic insulators, and metal C- rings.
When replacing the collector, Agilent recommends replacing
the ceramic insulators and metal C- rings.
1 Gather the following:
• NPD ceramic insulator kit (see
for the NPD" on page 260.)
• Collector
• Cap for the bead
• T- 10 and T- 20 Torx screwdrivers
• Tweezers
• Cotton swab
• Solvent
• Methanol
• Jet (see "Selecting an NPD Jet"
• Lint- free gloves
• Compressed, filtered dry air or nitrogen
The bead is delicate. Be careful not to break or crack the bead.
When performing maintenance on the NPD, avoid touching the bead
with your fingers, and prevent it from coming in contact with other
surfaces.
Set the bead voltage to 0.0 and Adjust Offset to Off.
2
Check and note the NPD leakage current for reference.
3
(See "To Check the NPD Leakage Current"
4 Load the GC maintenance method
become ready.
Be careful! The oven or detector fittings may be hot enough to
cause burns.
Remove the bead. (See
5
Assembly" on page 272.)
Maintaining the NPD
"Consumables and Parts
on page 264)
on page 285.)
and wait for the GC to
"To Replace the NPD Bead
14
279