visibility, <of a sign>
range of visual perception, normally measured in terms of the threshold distance, at which a sign becomes visible
Note 1 to entry: This entry was numbered 17-1400 in CIE S 017:2011.
visibility, <of a sign>
range of visual perception, normally measured in terms of the threshold distance, at which a sign becomes visible
Note 1 to entry: This entry was numbered 17-1400 in CIE S 017:2011.