, A Logarithm of the ratio of incident to transmitted radiant power through a sample (excluding the effects of sample cell walls). Depending on the base of the logarithm, a decadic and Napierian absor [..]

A measure of the amount of light absorbed by a sample. The absorbance (A) equals minus the base-10 log of the transmittance.

Used mostly by chemists, the negative logarithm (base 10) of the transmittance of an absorbing sample, often corrected for reflection by its container. Despite its name, absorbance is a consequence of [..]

Absorbance is a measure of the quantity of light absorbed by a sample.Also Known As: Optical Density, Extinction, Decadic Absorbance

(n) (physics) a measure of the extent to which a substance transmits light or other electromagnetic radiation

Absorbance is measured in the dimensionless unit, AU. To understand how this relates to transmission, we must consider the Beer-Lambert (or Beer’s) Law:

<investigation> 1. <chemistry> Absorbance is defined as a logarithmic function of the percent transmission of a wavelength of light through a liquid. 2. <microbiology> This can be used as a measure of the amount of light absorbed by a suspension of bacterial cells or a solution of an organic molecule, it is measured by a colourime [..]

A measure of the decrease in incident light passing through a sample into the detector. It is defined mathematically as: I = radiation intensity