# 17-24-103

coefficient of retroreflection

RA

quotient of the coefficient of luminous intensity, R, of a plane retroreflective surface and its area, A

where I is the luminous intensity of the retroreflector in the direction of observation and E is the illuminance at the retroreflector on a plane perpendicular to the direction of the incident light

Note 1 to entry: The coefficient of retroreflection is particularly suitable for describing materials in sheet form.

Note 2 to entry: Formerly, the symbol R′ was used for this quantity.

Note 3 to entry: The coefficient of retroreflection is expressed in candela per lux per square metre (cd⋅lx−1⋅m−2).

Note 4 to entry: This entry was numbered 845-04-97 in IEC 60050-845:1987.

Note 5 to entry: This entry was numbered 17-182 in CIE S 017:2011.

Publication date: 2020-12