Chapter 6 73
Maintenance
Chapter 6
Maintenance
Chapter 6 describes the maintenance of the Model 5380 PFPD.
Proper storage and handling of the detector components will ensure reliable
operation of the PFPD. Never handle tool parts that touch the internal parts of the
PFPD. Use clean lab tissues, the Teflon extractor device, or Teflon-coated forceps
to remove or replace internal detector parts. Place removed parts on a clean, lint-
free lab tissue or in a clean glass beaker.
Changing the Combustor
Replacement of the combustor may be necessary either when a combustor with
another internal diameter is needed or when the carbon emission (second peak)
begins to “tail” excessively (i.e., beyond 6 ms from the trigger point). When
conditioning a column attached to a Model 5380 PFPD, an old dirty combustor
should be installed in order not to contaminate a clean combustor.
This section describes how to replace the combustor and associated parts that are
housed within the detector body, and how to inspect the top of the GC column. See
Figure 6.1 for part names and numbers.
Note: Before changing the combustor, bakeout the PFPD overnight at 350°C.
Observe the carbon emission to see if the combustor has been cleaned. In
most cases, this procedure may be sufficient to clean the combustor. Also
note that the combustor is sensitive to dust. If the bakeout process fails to
clean the combustor, replace it.
Removing the Installed Combustor
1. Set the PMT voltage and ignitor current to zero using WinPulse. Turn the
Detector Controller off, and disconnect the PMT HV cable from the back of
the Detector Controller.
2. Allow the PFPD to cool to room temperature.
3. Remove the detector cap mounting screws (Part #295287C) using a U/yr" Allen
wrench. Place the screws on a clean lab tissue.
4. Lift the detector cap (Part #246900) off the detector body (Part #301333) and
place it upside down onto a clean lab tissue. Take care not to dislodge the
large aluminum washer (Part #288050) loosely attached to either the bottom
of the detector cap or the top of the detector body.
!
WARNING:
Handling the
PFPD while it is
hot can cause
serious burns.
!
CAUTION:
Due to high
temperatures, the
mounting screws
may become
increasingly
difficult to
remove. If any
resistance is
experienced in
removing them,
replace them with
new screws.
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