Agilent Technologies 6850 Series Service Information page 305

Refer to the following diagram for flow
measurement and troubleshooting:
EPC Module
Filter Proportional
valves
frits
Air in
Makeup in
H in
2
H makeup flow comes down the outside of the jet and up the
2
center, sweeping outside of the column. Since these flows are pressure controlled,
a restricted jet will reduce the H
restricted jet will reduce the H
Released: April 2004
FID gang fitting
Pressure
sensors Restrictors
PS
Air inlet
PS
H2/Makeup
gas inlet
PS
and makeup flows are pressure controlled, a
2
and makeup flows
2
6850 Series Gas Chromatograph Service Procedures
Partially clogged, restricted FID jet
A leak around the jet seal will result in correct H
measurement, however the H is not going through the jet
2
but around it. The flame will be unstable and hard to light.
A leak at the column fitting will allow H
oven. The flame will be difficult to light or keep lit.
flow
2
to leak into the
2
306