CO
2
Incubator BB 150 Operating Instructions
18
4.
Description of the device
4.3
Safety devices
The device is equipped with the following safety devices:
• A door switch interrupts the CO
2
supply and the work space heating when
the glass door is opened.
• An independent thermal protection protects the samples from harmful over-
heating in the event of a failure.
• A pressure compensation opening ensures pressure compensation in the
device work space.
• Audible and visual alarms indicate failures during operation.
4.4
Work space atmosphere
In the work space of the incubator, the particular physiological ambient condi-
tions for the preparation and cultivation of cell and tissue cultures are simula-
ted. The work space atmosphere is determined by the following factors:
• Temperature,
• Relative humidity,
• CO
2
concentration.
Temperature:
To ensure undisturbed operation, the temperature in the operating room must
be at least 18° C and the incubation temperature must be at least 3° C higher
than the room temperature.
The heating system controls the incubation temperature from this temperature
threshold up to 55° C. The principle of air jacket heating and the additional, se-
parate heating of the outer door minimize the risk of condensate formation on
the side walls, at the ceiling of the work space, and at the glass door.
Relative humidity:
The water tray of the work space can hold 3.0 liters of processed water. The hea-
ting of the work space causes evaporation of the water, thereby ensuring a con-
stant humidity within the work space. Under normal operating conditions and
at the usual incubation temperature of 37° C, a constant relative humidity of approx
95 % is achieved in the work space.
If heated containers are removed and put back into the work space, the elevated
humidity and the cooling may cause condensate to form on the outer sides of
the container.
For humidification, processed water of the following quality is required:
• demineralized and either distilled or autoclaved for sterilization,
or
• completely deionized and either distilled or autoclaved for sterilization.
CO
2
supply:
To ensure correct growth conditions for the cell and tissue cultures, the work space
is supplied with CO
2
. The pH of the bicarbonate-buffered culture media large-
ly depends on the CO
2
content of the work space atmosphere. The CO
2
con-
tent of the work space atmosphere can be controlled within a range of 0-20 %.
The CO
2
must be of the following quality:
• Purity 99,5 % min.,
or
• medical grade.
