ˈsektə(r)d- noun
also sector disk or sector wheel
: a disk with alternate opaque and open sectors used in photometers to vary the brightness in a known manner
ˈsektə(r)d- noun
also sector disk or sector wheel
: a disk with alternate opaque and open sectors used in photometers to vary the brightness in a known manner
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012