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How
Infrared Detector: Microbolometer
Signal Processor Unit: Circuit Board
HOW thermal WORKS
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thermal works
Infrared Energy
Video Signal
Thermal imaging systems, also called infrared cameras, detect the heat given off by an object or person and display the difference in white hot, black hot or color variations. Because different materials absorb and radiate thermal energy at different rates, an area that we think of as being one temperature is actually a mosaic of subtly different temperatures. So a person, warmer than the surrounding air, appears “white” while the cooler surrounding air or buildings will appear in varying shades of gray.
The infrared energy is scanned by a phased array of infrared-detector elements (microbolometers), which detect changes in temperature. The detector elements create a very detailed temperature pattern called a thermogram. It only takes about one-thirtieth of a second for the detector array to obtain the temperature information to make the thermogram. This information is obtained from several thousand points in the eld of view of the infrared detector. The thermogram created by the detector elements is translated into electric impulses. The impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display. The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the infrared emission.
Unlike traditional night-vision equipment, which uses image-enhancement technology, thermal imaging is great for detecting people or working in near-absolute darkness with little or no ambient lighting (i.e. stars, moonlight, etc,). It can display heat on a car that was just driven amongst others that were parked for some time.