Varian 450-GC, User Manual

Page: 142 / 205

Detectors – Flame Ionization Detector (FID)
Page: 292 User Manual 450-GC Varian, Inc.
MAINTENANCE
When the performance of the FID has degraded you may want to replace the
flame tip ferrule, or clean the deposits from the internal parts, including the
flame tip.
Clean the Flame Tip and Internal Parts
If the FID noise increases with frequent spikes, the internal parts may be
contaminated and need to be cleaned.
To clean the flame tip and the internal parts of the FID, proceed as follows:
Al ways h andl e detect or components w it h t weezers to avoid
contamination.
1. Remove the detector and internal parts (see disassemble the FID, on page
289).
2. Scrape the deposits from the bore of the collector tube, the insulator and
the metal part of the flame tip with emery cloth (e.g., SiO
2
).
3. If the flame tip is plugged, insert a wire through the flame tip orifice to clear
it.
4. If you have access to an ultrasonic cleaner, clean the collector, insulator
and flame tip with distilled water.
5. Rinse the cleaned components with methanol or acetone and air dry.
6. Wipe the detector tower with acetone.
7. Clean the probe arms with methanol and air dry or dry in an air oven
(maximum drying temperature of 150 °C).
8. Reassemble the FID, see Reassemble the FID, on page 290.
Use proper eye and skin protection. Methanol and acetone
are toxic and flammable chemicals. Exercise appropriate
care when you use and dispose of t hese substances.