Forma Series II 3110 Water-Jacketed co2 Incubators User Manual

Calibrating the O
2
System
Startup- Allow the temperature and the CO
2
of the cabinet to stabilize at
least 12 hours before proceeding.                                                            
Operating Unit - Allow CO
2
to stabilize at least 2 hours at setpoint before
proceeding.
To ensure accurate calibration, the unit will not allow CO
2
to be spanned
below 3%. If the cabinet does not contain at least 3% CO
2
, increase the
setpoint and allow the unit to stabilize before completing this procedure.
1. Measure the CO
2
concentration in the chamber through the gas sample
port with a Fyrite or other independent instrument. Several readings
should be taken to ensure accuracy.
2. Press the Mode key until the CAL indicator lights.
3. Press the right arrow until IR CAL XX.X appears in the message center.
4. Press the up/down arrow to adjust the display to match the
independent instrument reading.
5. Press Enter to store calibration.
6. After Enter is pressed, the unit will go into a calibration cycle that lasts
5 to 6 minutes. Control panel is locked during this calibration cycle.
7. Press the Mode key to return to Run Mode.
Models 3130, 3131, 3140 and 3141 have an O
2
control sensor. The sensor
is a fuel cell that puts out a linear millivolt signal based on O
2
content of
the chamber. The fuel cell depletes over time depending on required O
2
levels, therefore the system should be calibrated before each test
experiment, or at least every 6 months. 
There are two methods available to calibrate the O
2
system. 
•
The preferred method calibrates the system to the known ambient O2
value of 20.7% and checks the life of the sensor. This method should
be used whenever a new sensor is installed.
•
The second method available allows the system to be calibrated to an
independent reference instrument by entering an offset.
2-4
Water Jacketed CO2 Incubator
Thermo Scientific
Section 2
Calibration
IR CO
2
Sensor
Stabilization Times

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O
2
Offset Calibration
1. Press the Mode key until the CAL indicator lights.
2. Press the right arrow until the display reads O2 CAL@20.7%.
3. Press Enter.
4. OPEN DOOR appears on the display. Open the outer and inner
doors.
5. The display reads CALIBRATING. 
6. When calibration is complete, approximately 2 minutes, an audible
tone sounds and the display returns to O2 CAL@20.7%.
7. The O
2
display will change to 20.7.
8. Press the Mode key to return to Run.
A new O
2
span value is stored in memory for use as the 20.7% O2
reference point. The keypad/control panel is "locked-up" during
calibration. 
Caution If using an O
2
Fyrite, the accuracy of the instrument will be
greatly affected by the concentration of CO
2
in the cabinet. Refer to the
Fyrite operating manual. 
▲
Startup - Allow the cabinet to stabilize at least 12 hours before proceeding.
Operating Unit - Allow O
2
to stabilize at least 2 hours at set point before
proceeding.
Measure the O
2
concentration in the chamber through the gas sample port
with an independent instrument. Take several readings to ensure accuracy.
1. Press the Mode key until the CAL indicator lights.
2. Press the right arrow until O2 OFFS XX.X appears in the message
center.
3. Press the up/down arrow to adjust display to independent instrument
reading.
4. Press Enter to store calibration.
5. Press the Mode key to return to Run Mode.
Water Jacketed CO2 Incubator        2-5
Thermo Scientific
Section 2
Calibration
O
2
Calibration at 20.7%

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Relative Humidity
Stabilization Times
All Model 3100 Series incubators can be equipped with an optional direct
readout relative humidity sensor. This is a readout only of the chamber
relative humidity. It does not provide any control of the relative humidity
in the cabinet.
Startup - Allow 12 hours for the relative humidity and temperature in the
chamber to stabilize before proceeding.
Operating Unit - Allow at least  2 hours after temperature display reaches
setpoint for relative humidity to stabilize before proceeding.
1. Place an accurate independent instrument in the center of the chamber.
Allow at least 30 minutes for RH to stabilize. 
2. Press the Mode key until the CAL indicator lights.
3. Press the right arrow key until RH CAL XX appears in message center.
4. Press the up/down arrow to match the display to the independent
instrument.
5. Press Enter to store the calibration.
6. Press the Mode key to return to Run Mode.
If a reliable RH measuring device is not available, the display may be
calibrated to a typical level. 
1. Follow the RH stabilization periods outlined above. 
2. With a full humidity pan and stable temperature, the relative humidity
in the chamber will be 95%. 
3. Using Steps 3-5 of the relative humidity sensor adjustment above,
adjust the display to 95%. 
4. This calibration method should be accurate to within 5%.
2-6
Water Jacketed CO2 Incubator
Thermo Scientific
Section 2
Calibration
Calibrating Relative
Humidity

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