Absorption capacity
Introduction
The absorption coefficient describes how a material attenuates a wave when interacting with it. Depending on the type of wave, sound or electromagnetic, its study is addressed in two different disciplines: acoustics and optics.
Absorption coefficient in acoustics
The absorption coefficient or attenuation coefficient in acoustics is defined as the ratio between the energy absorbed "Absorption (sound)") and the energy incident by a surface or substance. Normally, it is expressed in Sabines on a scale of 0 to 1.
Because the absorption coefficient of a material varies with frequency, it is usually specified at frequencies of 125, 250, 500, 1000, 2000 and 4000 Hz.
The edge effect or diffraction effect is produced by wave diffraction at the edges of the material to be measured, so in this case we would have the acoustic absorption be greater than 1.
As this value will vary for each frequency, we cannot speak of a single coefficient "Coefficient (mathematics)").
The absorption coefficient must be taken into account when acoustically conditioning a room with materials that absorb sound, both in terms of the interior and its insulation from the exterior.
Absorption coefficient in optics
Contenido
El coeficiente de absorción, [ ], en óptica es un parámetro fundamental que permite cuantificar la capacidad que tiene un material para absorber la radiación electromagnética a medida que esta viaja a través de él. La ley empírica que relaciona la intensidad de radiación que incide en el material con la intensidad saliente , y el coeficiente de absorción , es la Ley de Beer-Lambert [1]:.
Experimentalmente, la atenuación de la luz se cuantifica mediante la densidad óptica usando una relación logarítmica entre la intensidad de entrada y la de salida [2] [3]:.
Ambas, la y la ley de Beer-Lambert, están unidas por una relación de proporcionalidad directa, que se obtiene de sustituir la forma exponencial dentro de la definición logarítmica de la :.