quotient of the regularly reflected part of the (whole) reflected flux and the incident flux
Note 1 to entry:
Note 2 to entry: The regular reflectance has unit one.
Note 3 to entry: This entry was numbered 845-04-60 in IEC 60050-845:1987.
Note 4 to entry: This entry was numbered 17-1076 in CIE S 017:2011.