Solving Detector Problems - Agilent Technologies 8355 Sulfur User Manual

6
Troubleshooting

Solving Detector Problems

92
A basic understanding of the detector helps to diagnose and
solve detector problems. Review the basic detector theory found
in "Theory of Operation"
section is intended to troubleshoot problems in a detector that
has previously been performing acceptably. If trying to optimize
a new detector application, see
Conditions" on page 53 for recommendations on adjusting
method setpoints to obtain better results.
Many symptoms may be caused by more than one problem or by
poor chromatographic technique. Analysis of sulfur or nitrogen
compounds has traditionally been very difficult because of the
inherent reactivity and instability of the compounds
themselves. Often, problems initially blamed on the detector
actually originate from either poor chromatographic technique
or other system failures (for example, a leak at the column inlet
fitting). Therefore, the first step in troubleshooting is to isolate
the problem to the GC (inlet, injector, or column), to the burner
assembly, or to the detector (ozone generator, vacuum pump,
photomultiplier tube, or electronics). When diagnosing a
problem in a system that had been working, a good first step is
to restore the default typical operating conditions. The response
under these conditions can help determine whether or not the
method settings are causing the problem.
As a good practice, use the GC's maintenance log and Early
Maintenance Feedback (EMF) features for the detector. This
feature helps you maintain the detector in good working order
before problems can arise. See the GC Operation Manual for
more information.
Also keep a maintenance log to track detector pressure readings
and background signal (the difference between ozone "on" and
ozone "off"). Changes over time in these values may indicate
maintenance due.
Table 11 in the next section lists many common problems, their
most probable causes, and corrective action that should be
taken.
on page 37. Also, please note that this
"Adjusting the Operating
SCD and NCD User Manual