Agilent Technologies 6890 Series, Service Manual, Page: 230 / 867

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Jun 2001
Detectors
Agilent 6890 Gas Chromatograph Service Manual
Flame Ionization Detector (FID) 310
Cleaning an FID jet and collector
Cleaning an FID jet and collector
Both the jet and collector bore require occasional cleaning to remove deposits
(usually consisting of white silica from column bleed or black, carbonaceous
soot). Such deposits reduce sensitivity and cause chromatographic noise and
spikes.
Cleaning the collector
Turn off the detector and its heated zone; also turn off gases to the detector
(particularly hydrogen). Allow time for the detector zone to cool.
1. Remove the collector as described in this chapter.
2. Use a cleaning brush (part no. 8710-1346) to scrub the interior of the
collector.
3. Use compressed air or nitrogen to blow out loose material from inside
the collector.
4. Wash the collector in distilled water, hexane and/or methanol. Dry in an
oven at 70° C for at least 1/2-hour.
Cleaning the jet
Turn off the detector and its heated zone; also turn off gases to the detector
(particularly hydrogen). Allow time for the detector zone to cool.
1. Remove the jet as described in this chapter.
2. Use a cleaning wire (0.016-inch od, 12 inch length, part no. 18765-20070)
to loosen/remove internal deposits.
3. Wash both the internal bore and exterior of the jet with a 1:1 (V/V)
solution of methanol and acetone.
4. Clean the detector base cavity using solvents, a swab and compressed air
or nitrogen.