Thermo Scientific Heracell 150i, Operating Instructions Manual

Page: 41 / 156

Operating Instructions | HERAcell® 150i / 240i
4 Description of the device 4 Description of the device 4 Description of the device
41
50115191 A / 08.2009
4.8 Sensor system
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
temperature and 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
at various locations next to the measuring cell:
• HERAcell
®
150i in the sidewall in the upper area [5],
• HERAcell
®
240i in the ceiling of the work space [4].
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 selected
set values. Based on this data, the control system
controls heating and CO
2
/O
2
/N
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 factory and cannot be changed. It protects the
stored cultures from overheating.
If the set temperature is exceeded by more than 1°C,
the thermal protection responds and the work space
temperature is automatically reduced to the selected
set value so that the incubation process can be
continued even in case of a failure. Any response of
the thermal protection will simultaneously trigger a
visual alarm.
If the thermal protection is enabled:
• an error message is issued,
• the alarm relay responds.
If the error message is accepted, the display shows the
Overtemperature icon to indicate the response of the
thermal protection, and the temperature display is
highlighted in red.
Fig. 11: Temperature,
CO
2,and
O
2 sensors