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6.4
UNITY–Air Server-xr Electronic Gas Control with the Thermo DPFC
A UNITY–Air Server-xr can be integrated into the DPFC system of a Thermo Electron GC. The DPFC module
regulates the carrier gas supply upstream of the UNITY–Air Server-xr and its pressure is monitored
downstream of the system in the septum purge line of the DPFC module. The split line of the DPFC
module remains unused.
6.4.1
Procedure
The carrier gas supply and the septum purge lines that normally run from the DPFC to the
split/splitless injector need to be cut and fitted with 1/8” brass unions (note: the carrier line requires
use of graphitised vespel ferrule with the 2 mm hole – part number Z-0402).
Extend these two lines with the length of green PEEK tubing so that they can reach the back panel of
UNITY-xr. The carrier gas line from the DPFC module should be connected to the UNITY–Air Server-xr
‘Carrier Inlet’ and the septum purge line should be connected to the ‘Pressure Outlet’.
Schematic of connections made between DPFC module and UNITY–Air Server-xr
6.4.2
Configuring the Thermo GC software
Having completed the physical connection between the Thermo Focus or Trace GC and UNITY–Air Server-
xr the next step is to configure the inlet settings.
The GC must be set up for back pressure regulation. To do this the DPFC must be removed and the
switches set in the correct position for purge & trap. Setting up this configuration is described in the
kit adapter for the purge and trap concentrator system installation guide.
The inlet that is being used to control the UNITY–Air Server-xr carrier gas supply should then be set to
operate in split mode but the split flow should be set to zero (off).
The only other important consideration is to ensure that the pressure of the carrier gas supplied to
the DPFC module is only 10-15 psi greater than the pressure that the DPFC module is required to
supply to UNITY–Air Server-xr.
DPFC
Module
Septum
Purge
Carrier
UNITY-xr
Pressure
Outlet
Carrier Inlet