Lux-Second

a unit of the quantity of illumination, or luminous exposure, in the International System of Units. Symbols, lk.sek (Russian); lx.s (international). One lux-second is the luminous exposure produced in 1 sec by an illumination of 1 Ix; 1 Ix.sec = 10^-4 phot.sec = 2.77 ×10^-8 phot.hr.