17
8.2.1.1
Control Mode
The Temperature Control can run in two different modes: Sample or Cage Feedback Mode. Press on
Control Mode icon
(see Figure 14 a) to choose which one you want to use, Sample or Cage Feedback
Mode. Figure 14 b shows how to select Cage Feedback Mode.
a
b
Figure 14. Chamber Mode Settings (a - b)
In this configuration the temperature of the air inside the cage is controlled, precisely in the position
where you have placed the NTC thermistor. It is strongly recommended to attach the NTC thermistor close to the
sample chamber, at right on the stage or on the top condenser (use a standard adhesive tape to fix the sensor on
those parts). The advantage of this solut
ion is that you don’t have to manually stick the fine gauge thermocouple
into a reference well. Once selected the CAGE feedback mode, the operator should calibrate the difference of
temperature between the air inside the enclosure (where the NTC thermistor has been placed) and the specimen
temperature (by sticking the fine gauge thermocouple into a reference well inside the Chamber Incubator), so to
find for instance that to keep the specimen temperature at 37°C, the cage temperature has to be at 38°C (see
paragraphs 8.2.1.5 and chapter 9). This means that when regulating the set-point, given that in this mode you
control the Cage’s temperature, this has to be set at 38
°C to keep the specimen at 37°C. This control mode is well
suited for multi-
user tasks where users don’t want to take care to correctly position the fine gauge thermocouple
into a reference well inside the chamber incubator; however, it is based on a calibration between cage and
specimen, therefore cannot be considered an active thermal control on the sample
Tip
►
Advantages of this Control Mode are: fast experiment start up and no specific action required in multi
user applications. The disadvantage is that it needs calibration between cage and specimen. The temperature
difference between the cage and the sample sensors depends on many factors like: the ambient temperature,
the enclosure design, the sensors position, but if these ones don’t change, the temperature difference doesn’t
change.
Figure 15 b shows how to select Sample Feedback Mode.
