Thermal Reference Images
The thermopgraphic images on
these pages represent the propagation of heat in micro-environmental systems.
This enables you to visualize temperature distribution patterns normally not
seen by the human eye. These images provide you with a far better understanding
of what is happening on your stage than the limited information on the numerical
displays of temperature controllers. The following thermographic images were
acquired at the Bioptechs facility. They were made under laboratory conditions
with the use of a calibrated thermographic camera. An infrared analysis program
was used to extract the temperature data and annotate the images.
Thermal Profile of a Bioptechs Delta T4
Visible Light Image of a Bioptechs Delta T4
The first Thermograph shows
the efficiency, accuracy and uniformity of the Delta T system. Notice the
temperature of the stage adapter. It is nearly the same temperature as the room
temperature background. Only the specimen and media are heated. Power
consumption is 0.9 watts because heat is only applied to the specimen area.
There is no heat transmitted to the stage. Therefore, it remains “Z” axis
stabile. This is a sharp contrast to traditional peripheral heating methods
(shown below), and clearly superior.
Thermal Profile of a Traditional Stage Heater
Thermal Profile of a Traditional Closed Chamber System
This thermograph indicates the disadvantage of peripheral heating. This is a
thermal model of a 50mm culture dish in the center of a 100mm diameter uniformly
heated, 3mm thick, aluminum plate with a 25 mm hole in the center. This image
was acquired after 20 minutes of equilibration. Note the high temperatures of
nearly 60 C, that it takes to reach 37 C in the specimen area. In this case heat
that is not beneficial to the specimen is sunk into the stage causing Z-axis
instability, not to mention the non-uniform temperature of the specimen area.
This thermograph shows a traditional geometry for a closed system chamber on a
peripherally heated plate equilibrated for 30 minutes. There are two 40mm
coverslips separated by a 0.5mm gasket sandwiched between a 100 mm heated
aluminum plate and an acrylic ring cover. Note the temperature of the heated
plate required to warm the center of the field. There is a two-degree difference
between the center of field and the acrylic plate, a nine-degree difference
between the heated plate and the specimen area. This plate is resting in free
air, not in contact with a stage plate that would sink much of the heat away
through conductivity. This excess heat transmitted to the microscope results in
“Z” axis variations. Also, due to the poor thermal conductivity you can see that
it would take a long time to re-equilibrate after perfusion.
Thermal Profile of a Bioptechs FCS2
Visible Light Image of a Bioptechs FCS2
The thermograph above demonstrates the uniform temperature
distribution of an FCS2. Notice that the coverslip temperature is so uniform
that its location, in infrared, is indistinguishable from the base of the
chamber. This demonstrates the effectiveness of the ITO heated Microaqueduct
slide. It is capable of re-equilibrating cell temperature within seconds of
perfusion and eliminates the typical thermal gradient that occurs with
peripheral heating.
Thermal Profile of a Bioptechs Objective Heater
Visible Light Image of a Bioptechs Objective Heater
Notice the temperature distribution in the following
locations: nosepiece, bottom of objective, region above heater band, and top of
objective. Power consumption after equilibration is 1.3 watts. The point is
that, unless you warm the entire microscope, the microscope will always act as a
heat sink with respect to warming the objective. You can expect a small thermal
gradient. All objectives have different thermal profiles. Therefore, it is
imperative to efficiently transfer heat to the core of the objective and prevent
excess heat from radiating from the heater-band. This is exactly what the
Bioptechs Objective Heater does! Check with Bioptechs for thermal information on
your objective.