A measure of the decrease in incident light passing through a sample into a detector.

a physical quantity, which expresses the amount of light absorbed by a sample solution. When a light beam passes through a sample, the amount of light absorbed is the difference between the incident radiation (Io) and the transmitted radiation (I). Absorbance is defined: A=-log Io/I.

a measure of the amount of light absorbed by (usually) a solution. Equal to the negative logarithm of the ratio of initial and final light intensity.

Units used to measure the amount of IR radiation absorbed by a sample. Absorbance is commonly used as the Y axis units in IR spectra. Absorbance is defined by Beerâ€™s Law, and is linearly proportional to concentration.

The absorbance is a manifestation of the Beer-Lambert Law and is defined as the logarithm to the base 10 of the ratio of the incident spectral irradiance to the spectral irradiance of transmitted radiation when only absorption is considered.

The ability of a material to absorb radiant energy. It is expressed as a negative common logarithm of transmittance.

Ratio of radiant energy absorbed by a body to the corresponding absorption of a blackbody at the same temperature. Absorbance equals emittance on bodies whose temperature is not changing. (A = 1 - R - T, where R is the reflectance and T is the transmittance.)

(A, D, E) optical density; extinction; decadic absorbance. A measure of the amount of light absorbed by a sample. The absorbance (A) equals minus the base-10 log of the transmittance.

The fraction of the incident radiation that is neither reflected nor transmitted by the sample. This term is also commonly, although incorrectly, used for log (1/Transmittance).

A.-The logarithm to the base 10 of the reciprocal of the transmittance, (T). A = log10 (1/T) = - log10 T

The ability of a medium to absorb radiation dependent on temperature and wavelength. Stated as a negative logarithm of the transmittance.

An optical property expressed as log (SIT), where T is the transmittance.

Negative logarithm (base 10) of the transmittance.