infrared(redirected from Far-infrared)
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denoting electromagnetic radiation of wavelength greater than that of the red end of the spectrum, i.e., of 0.75–1000 μm. Infrared rays are sometimes subdivided into long-wave or far infrared (about 3.0–1000 μm) and short-wave or near infrared (about 0.75–3.0 μm). They are capable of penetrating body tissues to a depth of 1 cm. Sources of infrared rays include heat lamps, hot water bottles, steam radiators, and incandescent light bulbs. Infrared rays are used therapeutically to promote muscle relaxation, to speed up the inflammatory process, and to increase circulation to a part of the body. See also heat.
in·fra·red (IR, ir),(in-fră-red'),
That portion of the electromagnetic spectrum with wavelengths between 730 and 1000 nm.
That portion of the electromagnetic spectrum with wavelengths between 770-1000 nm.
infraredthe electromagnetic radiation in the region between red light and radio waves. see ELECTROMAGNETIC SPECTRUM.
Radiant energy of wavelengths between the extreme red wavelengths of the visible spectrum and a wavelength of a few millimetres. The wave band comprising radiations between 780 and 1400 nm is referred to as IR-A. Excessive exposure to these radiations can cause visual loss (e.g. eclipse blindness) and cataract. The waveband comprising radiations between 1400 and 3000 nm is referred to as IR-B. Excessive exposure to these radiations can cause cataract and corneal opacity. The wave band comprising radiations between 3000 and 1 ✕ 106 nm (or 1 mm) is referred to as IR-C. Excessive exposure to these radiations can cause cataract (heat-ray cataract). See eclipse blindness; absorptive lens; infrared optometer.