1. The SI unit
, symbol lx
, equal to one lumen
per metre squared. The plural is unchanged lux.
Average light intensities are, very roughly:
- 100 lx inside a house
- 300 ~ 500 lx in a workplace
- 2 000 lx outside on a dull winter's day
- 10 000 lx outside on a bright summer's day
s adjust so that the difference in illuminance does not seem so enormous; also (thanks, Oolong
) illuminance is perceived logarithmically.
2. A brand of soap. (You knew that.)