A thermographic camera, sometimes
called a
FLIR (Forward Looking InfraRed), or an infrared camera less specifically,
is a device that forms an image using
infrared radiation, similar to a common camera that forms an image using
visible light. Instead of the 450–750 nanometer range of the visible light
camera, infrared cameras operate in
wavelengths as long as 14,000 nm (14 µm).
Infrared energy is just one part of the electromagnetic spectrum that encompasses
radiation from gamma rays, x-rays, ultra violet, a thin region of visible
light, infrared, microwaves, and radio waves. These are all related and differentiated
in the length of their wave (wavelength). All objects emit a certain amount
of black body radiation as a function of their temperatures. Generally speaking,
the higher an object's temperature is, the more infrared radiation as black-body
radiation it emits. A special camera can detect this radiation in a way similar
to an ordinary camera does visible light. It works even in total darkness
because ambient light level does not matter. This makes it useful for rescue
operations in smoke-filled buildings and underground.
