3.10 PC Control
OPTIC-4 can be controlled remotely from a host PC using the Evolution Workstation software
supplied with the instrument. Furthermore, methods can only be defined using this software.
3.11 Cryogenic Trap Options
The OPTIC-4 cryotrap is designed to solve problems with peak tailing and band broadening in
capillary gas chromatography. The trap can be used to focus volatile components in a narrow band
at the head of the column by cooling a short section of the column. Rapid cooling and heating
ensures an optimum peak shape and reproducibility.
There are two different version of the cryogenic trap options available – CO
2
and direct LN
2
(liquid
Nitrogen) cooled traps. Each option comprises a trap, a trap control board, and a cryogenic valve kit.
The trap is installed in the oven of the host GC and is connected to the control unit and either the
CO
2
bottle or the LN
2
pressurized vessel (not supplied). The cryotrap is fitted to OPTIC-4SC and
OPTIC-4DC and is available as an accessory for all other OPTIC-4 models.
NOTE:
Specific cryogenic valves supplied with the CO
2
or LN
2
cooling options cannot be used for
other coolants than specified.
3.11.1 Cryotrap Hardware
The cryotrap option consists of a control board inside the OPTIC-4 control unit, a trap, a cryogenic
valve, an isolated hose and a control cable. The heart of the trap is a small low thermal mass heating
device placed in a cooling chamber. It can be cooled to sub-ambient temperatures and rapidly
heated up to 350°C with 60 °C/sec. The trap is cooled either with CO
2
or liquid Nitrogen. After
trapping, the sample is released by a rapid resistive heating. The cooling and heating of the trap are
controlled by the OPTIC-4 control unit.
3.11.2 Trap Rear Panel Connections
The OPTIC-4 rear panel (Fig. 3.3) has connections for a trap heater ("Cryotrap Heater"), a trap
temperature sensor ("Cryotrap TC") and a trap cooling valve (“Cryotrap C. Valve”).
3.12 Auxiliary EFC Unit
The OPTIC-4D and OPTIC-4DC version are supplied with an auxiliary flow control unit. The "Aux In"
port is used connected to the auxiliary gas supply. "Aux Out" port is the exhaust outlet from the
auxiliary gas control channel and should be connected to target like the inlet backflush.
3.13 Master/Slave Mode
Depending on the way it is connected to the GC and autosampler, OPTIC-4 can be set to act as the
system “master” or system “slave” via the configuration menu in the Evolution Workstation
software. By default, OPTIC-4 is configured as a “Master”.
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