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Summary
DescriptionEmissivity differences on Chopfab beer can.png
English: The top image shows a false-color thermal image of the beer can with three measurement points applied. The bottom image shows a visible-spectrum image of the same scene.
One square each of duct tape (left) and electrical tape (right) have been applied to the can and are showing up as cold areas in the thermal image (measured as 17.5 °C). The black surface of the can is measured as 19.6 °C, while the reflective surface of the can is measured as 26.6 °C, as it reflects the heat of the room. The white logo also shows up as noticeably warmer. These differences are a measurement error introduced due to the different Emissivity of the surfaces.
The infrared image also shows a reflection of the can on the stone countertop. Because the countertop is partially reflective (in the infrared spectrum), attempting to measure the temperature of the countertop based on an infrared image would yield a value between the temperature of the countertop itself and the object being reflected, making an accurate measurement impossible.
Notes: Taken with a FLIR ONE Pro. Artificial blur was applied to the background of the visible-spectrum image, which was taken at the same time as the infrared image with the secondary camera built into the device. The lenses are slightly offset.
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An infrared image of a cold beer can on a stone countertop. Even though the surface has a mostly uniform temperature, the emissivity of the surfaces differs, causing large differences in the apparent temperature.