Agilent Technologies 8860 Maintaining page 200

12 Maintaining the NPD
To Maintain the NPD Collector, Ceramic Insulators, and Jet
17 Pull the jet straight out of the detector. Use tweezers, if necessary.
The adaptable NPD jet is longer than the capillary optimized NPD extended jet and should
C AU T I O N
never be installed in a capillary optimized detector.
18 Place the jet in the detector body.
19 Using a nut driver, tighten the jet 1/6 turn past finger-tight. Do not overtighten.
20 Attach the column to the detector.
21 Use a cotton swab wetted with solvent to clean the residue from the inside of the collector
22 Install the bottom metal C-ring, the lower ceramic insulator, and the top metal C-ring.See
23 Install the collector.
24 Install the upper ceramic insulator and top metal C-ring above the collector.See
25 Install the lid, making sure that the NPD lid standoffs are in their slots. Hold the lid flat while
26 Slide the electrometer interconnect into the slot on the lid and lower the electrometer into
27 Install the J-clamp and screws to secure the electrometer to the pallet.
28 The GC maintenance wizard will perform checks at the appropriate times, including Leak &
29 Select Finished, then select OK to exit the GC maintenance wizard.
30 Install the bead assembly and restore normal operating conditions. See
200
and around the jet. If the collector appears very dirty, replace it with a new one.
Figure 19.
each of the screws is tightened until they touch the lid. Tighten each screw evenly, 1/2 turn
at a time, until tight. Do not overtighten.
the mounting tray. Be careful not to touch or bend the spring.
Restriction tests, and will automatically reset the maintenance counters.
NPD Bead Assembly" on page 192. Do not reset the bead counter unless replaced.
After installing new collector parts, the NPD leakage current should be lower. See
Check the NPD Leakage Current"
for proper reassembly of the detector (especially where the electrometer interconnect
contacts the collector assembly) and for leaks.
on page 201. If the leakage current is abnormal, check
Figure 18.
"To Replace the
"To
Maintaining Your GC