Eppendorf R Series 48R CO2 Incubator User Manual
Page 50
50
CO48R-0050
Galaxy R Series 48 R Personal Size CO
2
Incubator
User’s Guide
NOTE:
At low oxygen levels, the CO
2
and O
2
levels may not have fully recovered
within the Alarm limits after the 15-minute “Delay in arming after door
opening.” This time period can be increased (in the ALARM screen) to
suit individual circumstances.
8. By controlling the Duty Cycle of the N
2
valve, Oxygen Control can be
tailored to achieve programmed Oxygen and Carbon Dioxide levels at
approximately the same time.
8.5.3 Operating
Guidelines
We recommend that you repeat the
OXYGEN SENSOR-REF TO ATMOSPHERE
procedure
(see Step 3 in Section 8.5.1 and further details in Section 8.5.4) once a month to ensure
that any long-term drift in sensor output will be corrected. Be sure to do it at the
chamber operating temperature.
When you are cleaning the chamber, be very careful not to wet the oxygen sensor or CO
2
sensor. Never use solvents on the sensor membrane; rather, be sure to cap the hydrophobic
filter before you clean. In fact, it is good practice to replace the filter each time you clean
the incubator chamber, to avoid the possibility of filter contamination.
Under normal relative humidity conditions (95-99%), the oxygen sensor’s performance
should not be affected. If, however, liquid condenses around the sensor, gas flow may
become restricted, giving the sensor a low signal. This may occur if there is a large
liquid spill inside the chamber or if the incubator is turned off while it is fully
humidified. Should such condensation
appear, normal operation can be restored by:
• removing the humidity tray,
• drying the chamber completely,
• and then running the incubator at 37°C for one hour.
This will dry out the sensor(s). The humidity tray can then be reinstalled and the
incubator can be safely re-humidified.
8.5.4 Referencing to Atmosphere
The oxygen sensor is a self-powered electrochemical cell that has a finite life dependent
on the ambient oxygen level. A typical lifespan is 1-2 years at atmospheric levels.
During the sensor’s lifespan, the signal produced will slowly degrade until it is
ultimately unusable. For this reason, we recommend that you reference the sensor to
atmospheric oxygen levels on a monthly basis.