2-2
Air Jacketed CO2 Incubator
VWR International
Section 2
Calibration
1. Press the MODE key until CAL indicator lights.
2. Press the right arrow until “TEMPCAL XX.X” appears in the message
display.
3. Press up/down arrow to match display to calibrated instrument.
4. Press ENTER to store calibration.
5. Press the MODE key to return to RUN or the right/left arrow to go to
next/previous parameter.
Model VWR51014991 (VWR catalogue number 10810-902) has a
thermal conductivity (T/C) CO
2
sensor. Thermal conductivity of the
incubator atmosphere is not only effected by the quantity of CO
2
present
but also by the air temperature and water vapor present in the incubator
atmosphere. In monitoring the effects of CO
2
, air temperature and
absolute humidity must be held constant so any change in thermal
conductivity is caused by a change in CO
2
concentration.
Changing temperature or changing from elevated humidity to room
ambient humidity levels will necessitate a re-calibration of the CO
2
control.
Some T/C CO
2
sensors go through an aging period, especially on new
installations. Calibration should be checked on a weekly basis, and
adjusted as necessary. When stabilization occurs, checks can become less
frequent.
T/C CO
2
Sensor Stabilization Periods
Start -Up
- The CO
2
sensor has been calibrated at the factory for 37°C
and elevated humidity. Allow the temperature, humidity, and CO
2
levels
in the chamber to stabilize at least 12 hours before checking the CO
2
concentration with an independent instrument.
Presently Operating
- Make sure the chamber doors are closed. Allow at
least 2 hours after the temperature and CO
2
displays reach their setpoints
for chamber atmosphere stabilization.
Temperature
(continued)
Thermal Conductivity
CO
2
System
