Preventive Maintenance
Flame ionization detector (FID)
177
Interconnect
Sprin
g
FID Signal Board Interconnect
Figure 8-13
9. Reassemble the detector cover.
Ignition problems
Before proceeding, make sure that gases are plumbed correctly, the
system is leak•free,flow rates are set correctly, and external lines have
been well purged.
Note: If Helium is being used as carrier/makeup gas, be aware that
flame lighting problems may occur at very high flow rates ( > 50 ml/min).
If problems arise with He carrier/makeup gas, try using the lowest flow
rate possible, consistent with obtaining good chromatography.
Assuming these things are correct, that the detector is contaminant•free,
and that the ignitor is operational, if ignition problems persist, a
damaged jet may be the cause.
Remove and inspect the jet, looking for galled or scored sealing surfaces,
burrs, a bent or crimped tube, etc. Even if no external damage is visible,
the jet may be damaged internally by overtightening. For this reason, it
