Varian 450-GC, User Manual

Page: 143 / 205

Flame Ionization Detector (FID) - Detectors
Varian, Inc. User Manual 450-GC Page: 293
Replace the Flame-Tip Ferrule
After a period of prolonged use, the flame-tip ferrule may deteriorate and crack.
As a consequence, a leak may develop around the base of the flame tip
assembly that causes unstable baseline noise and reduced sensitivity. In this
situation, or when the detector is to be operated at temperatures above 400 °C,
you must replace the ferrule. Be sure to select the proper ferrule for the
application. The Vespel/graphite ferrule has a maximum temperature limit of
400 °C see Figure 45on page 288.
Varian recommends to NOT using other ferrules then those listed. Due to small
dimensional variations common in these ferrules leaks on higher temperatures
are possible.
FID Test Chromatogram
For an FID test chromatogram see section Detector Test Chromatograms, on
page 420.