Similar in shape to a camera, a thermal imager is a device that leverages infrared radiation to form an image from the simple measurement of small, relative temperature differences within and among objects. The imager detects these temperature differences and converts the otherwise invisible heat patterns into clear, visual data that can be seen through a viewfinder or monitor. While the device cannot see through walls, glass, or other solid objects, it can detect heat that has radiated toward the surface of those objects.
Using different infrared wavelengths, the imager measures the thermal signature of a particular area ranging from anything as small as an electric box to an object as large as an entire building frame. The device then interprets the data it collects and presents it to the user as a colorized representation of the heated areas, making it easy to detect places of thermal variance. The device does not measure temperature directly, but rather, the energy that has radiated out from the presence of thermal variance.
The thermal imager includes a series of components that allow it to do its job. A special lens is used to focus the infrared light waves coming from all the objects in its view. The focused light is then scanned by the device’s internal infrared detector elements, creating electric impulses. These impulses are then sent to the imager’s signal processing unit, which ultimately translates the information into visual data for its display. The final result is a thermographic representation of the selected area, or in simpler terms, a picture showing the spectrum of heat signatures that a person couldn’t ordinarily see with their naked eye. The spectrum appears as various colors depending on the intensity of the infrared emissions.
There are a few things that you will have to consider if you are going to invest in a thermal camera.
Aside from the design, durability, and the overall construction of the camera, you also need to make sure that you know more about the passive infrared sensor used by the camera.
How good is its body heat detector feature?
A passive infrared sensor measures the infrared light within its field of view that radiating from an object.
Also, you will have to know more about the difference between near-infrared and long-wave infrared.
Near-infrared, as the name suggests is found infrared within the wavelengths 800 to 2500nm. On the other hand, the long-wave infrared is collected within the 8 to 15 µm wavelength.
It matters to check the sensitivity of the thermal camera you are going to use. Some are sensitive in detecting 0.10°C changes while on the other hand, there are those cameras that can detect 0.5°C.
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