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Absorption coefficient

The absorption coefficient α is a property of a material. It defines the extent to which a material absorbs energy, for example that of sound waves or electromagnetic radiation. Wallace Sabine was a pioneer of this concept in acoustics and defined the unit of the Sabine. A Sabine is defined as a fraction of acoustic power absorbed by a 1m square of open window. In SI units, absorption coefficient is measured in inverse metres, and is represented by the Greek letter α.

Sound Absorption Coefficients for Some Common Materials - This website helps one understand the concept as well as provides formulae and some coefficients.

In chemistry and biological sciences, the absorption coefficient is a measure of the solubility of a gas in a liquid measured as the volume of the gas (taken under standard conditions) that saturates a unit volume of the liquid.

Absorption coefficient is sufficient for describing energy propagation through a homogeneous system only. Propagation through a heterogeneous system is affected by scattering,[1]. There is more general term attenuation that takes into account both absorption and scattering. It is widely used in acoustics as attenuation coefficient for characterizing particle size distribution. [2],[3].

See also


  1. ^ Bohren,C. F. and Huffman, D.R. "Absorption and Scattering of Light by Small Particles", Wiley, (1983), isbn= 0-471-29340-7
  2. ^ Dukhin, A.S. and Goetz, P.J. "Ultrasound for characterizing colloids", Elsevier, 2002
  3. ^ ISO 20998-1:2006 "Measurement and characterization of particles by acoustic methods"
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Absorption_coefficient". A list of authors is available in Wikipedia.
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