Thermo 3010 Series, Руководство по эксплуатации и техническому обслуживанию, Страница: 14 / 37

Model 3010 Incubator ________________________________________________________________________Calibration
2 - 1
Section 2 - Calibration
After the unit has stabilized, the air temperature and CO
2
display reading can be calibrated to reference instruments.
Calibration frequency is dependent on use, ambient condi-
tions, and accuracy required. Good laboratory practice would
require at least an annual calibration check. On new installa-
tions, all parameters should be checked after the stabilization
period.
Prior to calibration, the user should be aware of the follow-
ing system functions. While the unit is in Cal Temp Mode, tem-
perature control is stopped so that chamber temperature remains
stable. When the unit is in Cal CO2 Mode, CO
2
control is
stopped so that CO
2
levels remain stable. If no keys are pressed
for approximately five minutes while in either of these two
modes, the system resets to Run Mode so control can be reacti-
vated.
Before making an adjustment or calibration to the
unit, it is imperative that all reference instruments
be properly calibrated.
2.1 Calibrating the Temperature
Place the calibrated instrument in the center of the cham-
ber. The instrument should be in the airflow, not against the
shelf. Before calibration, allow the cabinet temperature to sta-
bilize.
Temperature Stabilization Periods
Start-Up - Allow 12 hours for the temperature in the cabinet to
stabilize before proceeding.
Operating Unit -Allow at least two hours after the display
reaches setpoint for the temperature to stabilize before proceed-
ing.
1. Press the Mode key until the Cal Temp indicator lights.
2. Press the up/down arrow to match the display to a cali-
brated instrument.
3. Press Enter to store the calibration into memory.
4. Press the Mode key to return to Run mode.
2.2 Calibrating Thermal Conductivity CO
2
System
This model 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 tem-
perature and the water vapor present in the incubator atmos-
phere. In monitoring the effects of CO
2
, air temperature and
absolute humidity must be held constant so any change in ther-
mal conductivity is caused only by a change in CO
2
concentra-
tion.
Changing temperature or changing from elevated humidity
levels to room ambient humidity levels would necessitate a
recalibration of the CO
2
control.
T/C CO
2
Sensor Stabilization Periods
Start-up - The CO
2
sensor has been calibrated at the factory for
37°. Allow temperature, humidity, and CO
2
levels in the cham-
ber to stabilize at least 12 hours before checking the CO
2
con-
centration 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.
1. Make sure stabilization periods outlined above are fol-
lowed.
2. Sample the chamber atmosphere through the sample port
with an independent instrument. Sample the atmosphere
at least 3 times to ensure the accuracy of the instrument.
3. Press the Mode key until the Cal CO2 indicator lights.
4. Press the up/down arrow to change the display to match
the independent instrument.
5. Press Enter to store calibration.
6. Press the Mode key to return to Run Mode.