Kendro HERAcell 150, Operating Instructions Manual

Page: 24 / 251

CO
2
Incubator HERAcell ® 150 Operating Instructions
24
4. Description of the device
4.6 Sensor system
Fig. 7: The blower wheel and two sensor modules are integral
to the baseplate [1] of the measuring cell:
• Sensor [2] for the acquisition of the work space tempera-
ture and of the thermal protection,
• CO
2
sensor [3] for the acquisition of the CO
2
content in the
work space atmosphere.
The O
2
sensor (optional) [4] for the acquisition of the O
2
content
in the work space atmosphere is installed in the upper area of
the right sidewall.
The sensor for the acquisition of the work space temperature
as well as the CO
2
sensor and the O
2
sensor are integral to
the control system of the device. Their measured values are
compared to the set nominal values. Based on this data, the
control system controls heating and CO
2
/O
2
supply.
The blower intermixes the supplied gases and ensures an even
temperature distribution within the work space.
The thermal protection has been preprogrammed at the fac-
tory and cannot be changed. It protects the stored cultures from
overheating. If the temperature is exceeded by more than
1° C, the thermal protection responds and the work space tem-
perature is automatically reduced to the set nominal value so
that the incubation process can be continued even in case of
a failure. Any response of the thermal protection will simulta-
neously trigger a visual alarm.
4.7 Door switch
A door switch [1] is installed at the upper edge of the work space
opening. If the door switch is activated by opening the glass
door, the gas supply and the heating of the work space are in-
terrupted and the display shows a corresponding message.
If the door remains open for more than 30 seconds, a short
acoustic alarm sounds. If the door remains open for more than
10 minutes, the acoustic alarm sounds continuously.
The outer door can only be closed after the glass door has been
latched properly.
NOTE – Version with gas tight screen
For devices with the optional gas tight screen,
the door switch function described above is
triggered when the outer door is opened.
Fig. 7
CO
2
and O
2
sensors
Fig. 8
Door switch