Retroflective Ceramic Markers

Horizontal entrance angle shall mean the angle in the horizontal plane between the direction of incident light and the normal to the leading edge of the marker. Observation angle shall mean the angled at the reflector between the illumination axis and the observation axis. Coefficient of Luminous Intensity (CIL) shall mean the ratio of the luminous intensity of the retroreflector in the direction of observation to the illuminance at the retroreflector on a plane perpendicular to the direction of the incident light. For markers, CIL is expressed in millicandelas per incident lux (mcd/lx). The equivalent English term is Specific Intensity (SI) expressed in candles per foot candle (cd/ft c).