CB (E6.1) 07/2017 Page 43/145
6.3 Deactivating the O
2
control and O
2
/N
2
pressure alarms (chamber with O
2
control)
6.3.1 Required gas supply of the chamber with O
2
control
In the chamber with O
2
control, cell growth can be additionally influenced by a variable oxygen content.
Depending on the required range of O2 concentration, the type of gas which is required may vary:
• Hyperoxic range (> 22 vol.-% O
2
)
As compared to the ambient air (O
2
concentration of 20.9 vol.-%) only the O
2
concentration needs to be
increased, no nitrogen is required for the O
2
control. Therefore, it is not necessary to connect a N
2
cylinder. You can deactivate the N
2
pressure alarm in the menu “Menu > Controller mode > O2 control”
(chap. 6.3.2).
• Hypoxic range (< 20 Vol.-% O
2
)
As compared to the ambient air (O
2
concentration of 20.9 vol.-%) only the N
2
concentration needs to
be increased, no oxygen is required for the O
2
control. Therefore, it is not necessary to connect an O
2
cylinder. You can deactivate the O
2
pressure alarm in the menu “Menu > Controller mode > O2
control” (chap. 6.3.2).
• Hyperoxic and hypoxic range or range from 20 vol.-% O
2
up to 22 vol.-% O
2
N
2
and O
2
are required for O
2
control. It is necessary to connect all gas supplies.
• Operation without O
2
control
You can deactivate the O
2
control in the menu “Menu > Controller mode > O2 control” (chap. 6.3.2).
With this setting, no alarm messages for O
2
and N
2
(pressure or concentration) will be issued.
Since neither nitrogen nor oxygen are required, it is not necessary to connect an O
2
or N
2
cylinder. No
O
2
and N
2
pressure alarms will be issued with deactivated O
2
control.
The zero-voltage relay alarm contact (chap. 11.6) for messages of deviation of the O
2
concentration
will also not be triggered.
Overview
Hyperoxic range
(>22 vol.-% O
2
)
Hypoxic range
(<20 vol.-% O
2
)
Hyperoxic and
hypoxic ranges
No O
2
control
O
2
control (with O
2
concentration alarm)
active active active
off
Connection of O
2
cylinder connected not connected connected not connected
O
2
pressure alarm active
off
active off
Connection of N
2
cylinder not connected connected connected not connected
N
2
pressure alarm
off
active active off