GE AKTAprocess, Operating Instructions Manual

Page: 60 / 180

3.3.6 Air trap
Introduction
An air trap is installed in the flow path of ÄKTAprocess. This section describes the air trap
and the sensors that are used for liquid level control.
Air trap function
The function of the air trap is to de-gas buffers. A vortex is created in the air trap and
the liquid in the air trap is pressed downwards and outwards by the centrifugal force
generated while air is separated in the center of the chamber. The rotation eliminates
pockets of stagnant liquid, which prevents unwanted build-up of solids (e.g., bacterial
cells) and simplifies the cleaning of the air trap.
Level sensors
Two sensors for automatic liquid level control are installed in the air trap. This sensor
assembly consists of a high and a low level sensor. The sensors must be re-calibrated
if the LED indicator displays a red light while the liquid level is still far from the low or
high level markers.
It is recommended that after a power down a calibration of the level sensors
should always be performed. See Section 6.6.2 Air trap calibration, on page 153.
Note:
When the air trap is filled with liquid that foams easily, for example liquids
containing detergents and protein solutions (sample), large volumes of air
should not be allowed to enter into the air trap. If foam is formed it may
interfere with the automatic liquid level control. Note:
Always position a movable air sensor at the inlet of the sample or detergent-
containing liquid. The air sensor will set the system to Pause when air is de-
tected, which will prevent the build up of foam in the air trap or can trigger
the next step in the method.
60 ÄKTAprocess Operating Instructions 29-0252-49 AA
3 System description
3.3 Standard components
3.3.6 Air trap