Since no object is detected alone and in a vacuum, other sources of EM radiation will possibly be transmitted through the subject and into the camera as well.įor a given temperature, different materials emit thermal radiation at widely varying levels. Materials transmit certain wavelengths of light as well, absorbing some, reflecting others. Understanding absorption is relevant for the other factors influencing the radiation detected by the camera. What are the thermal properties of the thing we are trying to measure? This depends on a few factors:ĭifferent materials absorb certain wavelengths of light at varying levels, affecting their thermal energy. Thermal cameras need to be aware of a few properties in order to work properly. So, with an array of bolometers, we've got the basic means of detecting IR radiation from an object, which, as part of the thermal radiation as a function of the objects temperature, means we can begin to depict the thermal scene on our own terms. Since all matter is emitting IR light as a result of blackbody radiation and is a function of its temperature, being able to accurately sense the IR radiation can allow us to create a thermal image. All electromagnetic radiation carries energy, but infrared light is more readily absorbed by matter, which increases its kinetic energy, therefore increasing its temperature. Infrared light, or IR, consists of the long wavelengths of light just beyond our visual perception of nearer red wavelengths in the visible spectrum. As their temperature increases, objects begin to emit light in the visible spectrum, beginning with a dim red glow before reaching a white hot (which means it's covering most of the visible spectrum) and eventually releasing most of that energy in ultraviolet wavelengths and beyond. Around room temperature, most objects emit this radiation at infrared wavelengths. This property is referred to as blackbody radiation. All matter above absolute zero (−459.67☏) emits electromagnetic radiation as a function of its temperature.
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