Lighting The Fpd + Flame - Agilent Technologies 7890 Series Advanced Operation Manual

Lighting the FPD
Advanced Operation Manual
Table 53 Recommended flows
Carrier (hydrogen, helium, nitrogen, argon)
Packed columns
Capillary columns
Detector gases
Hydrogen
Air
Carrier + makeup
Helium, either as carrier or makeup gas, may cool the
detector gases below the ignition temperature. We
recommend using nitrogen rather than helium.
+
flame
Before trying to light the flame, heat the detector to
operating temperature and let it stabilize.
During the ignition sequence, the detector does the following:
Until the detector temperature zones reach setpoint, the
1
GC purges the detector with all gas flows.
Once the detector stabilizes at its thermal setpoints, the
2
GC turns off hydrogen and makeup gas flows. Carrier and
air flows remain on.
Sets air flow to 500 mL/min.
3
Turns the glow plug ignitor on.
4
Ramps the hydrogen flow from 10 to 70 mL/min.
5
Resets the air flow to the air flow setpoint.
6
Resets the hydrogen flow to the hydrogen flow setpoint.
7
Turns the makeup gas on.
8
Compares the signal change with the Lit offset value. If the
9
change is greater than Lit offset, declares the flame on
(lit). If it is less, declares the flame off (not lit).
For this process to work, there must be enough air pressure
to the pneumatics module to provide up to 500 mL/min
flow. We recommend a supply pressure of at least 60 psi.
See the Installation and First Startup
Detectors
mL/min
10 to 60
1 to 5
60
60
60
manual.
5
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