far-infrared radiation

American  

[fahr-in-fruh-red] / ˈfɑr ɪn frəˈrɛd /

noun

1. the longer wavelengths of electromagnetic radiation in the infrared region of the spectrum, beyond the red end of the visible spectrum, from 50 to 1000 micrometers. FIR

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far-infrared radiation Scientific  

/ fär′ĭn′frə-rĕd′ /

1. Infrared electromagnetic radiation of very long wavelengths, in the range of 2–50 microns. It is used in medicine to provide a penetrating heat to the body.

2. Also called far-red radiation

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