NCIt definition : A SI derived unit of illuminance equal to the direct illumination on a surface that
is everywhere one meter from a uniform point source of one candela; a unit of illuminance
that is equal to one lumen per square meter.;
Alternative definition : CDISC: A unit of illuminance equal to the direct illumination on a surface that is
everywhere one meter from a uniform point source of one candela; a unit of illuminance
that is equal to one lumen per square meter.(NCI);