Kendro HERAcell 150, Operating Instructions Manual

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CO
2
Incubator HERAcell ® 150 Operating Instructions
22
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
and O
2
supply and the work space heating
when the glass door is opened.
• The optional gas guard switches the gas supply over to a full gas cylinder.
• An independent thermal protection protects the samples from harmful over-
heating in case of failures.
• 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,
• O
2
concentration (option).
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 this 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 and glass door/gas tight screen minimize the
risk of condensate formation at the side walls, at the ceiling of the work space,
and at the glass door/gas tight screen.
Relative humidity:
The water tray of the work space can hold 3.0 liters of processed water. The hea-
ting of the work space supports the condensation of the water, thereby ensu-
ring a constant 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.
A high/low switch-over function allows the selection of two humidity settings:
• Select
setting 0 (High) for a relative humidity of approx 95 %
(standard setting).
• Select setting I (Low) for a relative humidity of approx 90 % .
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.
The low humidity regulation effectively prevents the formation of conden-
sate on containers.