Agilent Technologies 6890 Series, Service Manual, Page: 310 / 867

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Jun 2001
Detectors
Agilent 6890 Gas Chromatograph Service Manual
Electron Capture Detector (ECD) 340
Maintaining an ECD detector
Maintaining an ECD detector
ECD bakeout
If your ECD baseline is noisy or the display frequency is too high (i.e.,
≥
100),
you should perform a thermal cleaning (also called a “bakeout”) of the
detector. Before performing a bakeout, verify that the carrier supply gas and
flow system are leak- and contaminant-free.
Caution Detector disassembly and/or cleaning procedures other than thermal should
be performed only by personnel trained and licensed appropriately to handle
radioactive materials. Trace amounts of radioactive
63
Ni may be removed
during these other procedures, causing possible hazardous exposure to
β
- and
x-radiation (bremsstrahlung).
WARNING To prevent possible hazardous contamination of the area with radioactive
material, the detector exhaust vent must always be connected to a fume hood,
or otherwise vented in compliance with the latest revision of Title 10, CFR,
Part 20, or with state regulations with which the Nuclear Regulatory
Commission has entered into an agreement (USA only). For other countries,
consult with the appropriate agency for equivalent requirements.
1. Record the ECD “Output” value from the GC display. If the number is
equal to or greater than 100, continue with this procedure.
2. Turn off the anode purge and makeup gas flows.
3. Remove the column from the detector.
4. Cap the bottom of the makeup gas adapter with a blank column ferrule
and column nut.
5. Set the makeup gas flow rate between 50 and 60 mL/min. Set the detector
temperature between 350 and 375°C.