Removing/Replacing The Npd Collector - HP 5890 Series II Plus Reference Manual

Preventive Maintenance
Nitrogen-phosphorus detector (NPD)
Caution Do not overtighten the jet! Overtightening may permanently deform
and damage the jet, the detector base, or both.
8. Replace the NPD collector, and transformer and cover assembly. Be
certain the spring contact to the signal board is in good contact with
the groove on the collector (see Figure 8•13).During reassembly do
not touch the lower portion of the collector assembly because
fingerprints and/or other contamination may (will) cause baseline
drift and/or noise.

Removing/replacing the NPD collector

Figure 8-16
Collector Body
NPD Collar
NPD Active Element
Cross-Section, Assembled Type A NPD Collector
Note Position of Collector
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