A measure of the extinction due to absorption of monochromatic radiation as it traverses a medium. Usually expressed as a volume absorption coefficient, , with units of reciprocal length (i.e., area per unit volume), but also as a mass absorption coefficient, , with units of area per unit mass. The two are related by , where Ï is the density of the absorber. See also absorption optical thickness.
A measure of the amount of radiant energy, incident normal to a planar surface, that is absorbed per unit distance or unit mass of a substance.
A rating of a material that tells how much sound energy it absorbs at given frequencies. Measured in Sabines. see also Sabine
Ratio of the absorbed amount (uptake)of a substance to the administered amount (intake): for exposure by way of the respiratory tract, the coefficient is the ratio of the absorbed amount to the amount of the substance (usually particles) deposited (adsorbed) in the lungs. RT absorbed dose. SN absorption factor. IRPTC, 1982
Efficiency of a material to absorb sound at a particular frequency (which relates to sound wave length and material thickness).
Factor describing light's ability to be absorbed per unit of path length.
a measure of the rate of decrease in the intensity of electromagnetic radiation (as light) as it passes through a given substance; the fraction of incident radiant energy absorbed per unit mass or thickness of an absorber; "absorptance equals 1 minus transmittance"
describes how strong a material absorbs light of a certain color. In medical optics the absorption coefficient is often represented with the greek letter 'mu' and a subscript 'a'. The units [1/cm] are common.
The sound absorption coefficient defines the fraction of sound energy absorbed by, for example, one reflection from a wall. Energy is proportional to the square of sound pressure, so for an absorption coefficient of 0.2, 20% percent of the energy is absorbed, reducing the sound pressure by 10.6%.
The energy of sound waves being taken in (entering) the surface of any material rather than being bounced off or reflected; usually given in octave bands. Materials are rated in terms of their ability to absorb sounds.
A numerical quantity that indicates the relative effectiveness of a material substance such as a gas in absorbing electromagnetic radiation.
In reference to a solar energy conversion devices, the degree to which a substance will absorb solar energy. In a solar photovoltaic device, the factor by which photons are absorbed as they travel a unit distance through a material.
It is defined per the following equation I(x) = I0 exp(-ax) Where I and I0 are transmitted and incident intensities, respectively on a film or substrate, and x is the material thickness. For example the absorption coefficients of polyimide at 248 nm and 308 nm wavelength are 2.8 x 105 cm-1 and 1.2 x105 cm-1, respectively.
An indicator of a material's internal absorptance. If the unit of transmission of the material is t, the absorption coefficient (a) is: a = -loget Learn more about Absorption Coefficient...
The ratio of energy absorbed by a medium or material to the energy incident on the surface. If a flux through a material decreases with distance in proportion to e-ax, th en is called the absorption coefficient. Also known as the absorption factor; absorption ratio; coefficient of absorption.
a number that is proportional to the "amount" of light removed from a sight path by absorption per unit distance.
A numeric measure of the amount of light energy that water itself and the dissolved and suspended substance within the water take up, which results in less energy or less light penetrating down into a water body. It can be measured for some or all of the wavelengths of a light ray and is reported by meter. It is an inherent optical property.
The ratio of the sound absorbed to the sound incident on the material or device.
The degree that sound is absorbed when struck by a sound wave. The scale goes from 0 to 1. 0 being no absorption, 1 being perfect absorption. Absorption Coefficients may be reported per frequency or as a one-number average See NRC or Noise Reduction Coefficient.
The proportion of incident sound that is absorbed by a surface. Usually this is expressed as a number between 0 and 1, or a percentage. In most materials, the amount af absorption changes with the angle of incidence. The specification is normally a 'random incidence' measurement.
The absorption coefficient 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.
