absorptance absorptance /əbˈzɔːrptəns/

noun

1. 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 , absorption coefficient , coefficient of absorption )
   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
   absorptance equals 1 minus transmittance