spectral absorptivity, <of an absorbing material>
spectral internal absorptance of a layer of an absorbing material such that the path of the radiation is of dimension length, and under conditions in which the boundary of the material has no influence
Note 1 to entry: to entry: The unit of the quantity length has to be specified. If a new unit of length is used that is
Note 2 to entry: The spectral absorptivity has unit one.
Note 3 to entry: This entry was numbered 845-04-88 in IEC 60050-845:1987.
Note 4 to entry: This entry was numbered 17-1209 in CIE S 017:2011.