Absorptivity

absorptivity

[əb‚sȯrp′tiv·əd·ē]

(analytical chemistry)

The constant a in the Beer's law relation A = abc, where A is the absorbance, b the path length, and c the concentration of solution. Also known as absorptive power. Formerly known as absorbency index; absorption constant; extinction coefficient.

(thermodynamics)

The ratio of the radiation absorbed by a surface to the total radiation incident on the surface.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Absorptivity

 

(or absorptive power), α_v, the fraction of a monochromatic radiation flux of frequency v that is absorbed by a body on which the flux is incident. Although often called the absorption factor, it differs from the absorption factor in that it applies only to radiation of a specific frequency. The absorption factor is the integral of the absorptivities over all the frequencies present in the irradiating flux. The absorptivity for thermal radiation is dependent not only on the frequency or wavelength of the radiation but also on the temperature T of the body:

α = α(ν, T) = α*(λ, T)

REFERENCE

Landsberg, G. S. Optika, 4th ed. Moscow, 1957. (Obshchii kurs fiziki, vol. 3.)

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.