- 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. Abbreviation: FIR
Also called far-red radiation [fahr-red] /ˈfɑrˈrɛd/.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- 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. Also called far-red radiation
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.