Agilent Technologies 6850 Series II User Information page 202

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Released: March 2004
Make sure the detector is operating under normal conditions and that at
least 2 hours have lapsed since the last run.
Check the output value. If it differs considerably from the normal output
level—either too high or too low—you should continue with this
procedure to identify the cause of the abnormal reading.
Use an electronic leak detector to check for leaks at the inlet and detector
and the column fittings. Correct leaks and then check the output level. If it
is still abnormal, continue to
The detector itself is not a likely source of leaks, so you should leak test
the inlet if the output reading is still abnormal. See the maintenance
material for your inlet in:
• "Maintaining a split/splitless inlet" on page 120
• "Maintaining a purged packed inlet" on page 134
• "Maintaining a PTV" on page 150
• "Maintaining a cool on-column inlet" on page 166
If the inlet is not leaking, go to
If the inlet is leaking, correct the leaks and check the output. If it is still
abnormal, the detector also may be leaking. Go to
Follow the leak test for the detector later in this document.
If the detector is not leaking, the cause of the problem is contamination.
Go to step 5.
If the detector is leaking, correct the leaks, and then recheck the output. If
it is still abnormal, go to
Check for contamination:
a. Remove the column and plug the detector connection with the cap
(part no. 19234-20650) and cap nut (part no. 19234-20570).
b. Run the detector at your normal operating conditions but with only
makeup gas flowing through it. Monitor the output. If it is normal for
your detector, then the contamination is from another part of the GC
system. Go on to
c. If the output is abnormal, then the detector is contaminated. Perform
a thermal bake out to decontaminate the detector. The procedure is
described later in
6850 Series II GC User Information
Maintaining a Microcell Electron Capture Detector (µECD)
step 3.
step 4 to check for leaks in the detector.
step 5.
step 6.
"Thermal cleaning" on page
Routine Maintenance: Detectors
step 4.
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