lumen
"A luminous flux unit which is equal to the luminous flux emitted into 1 steradian by a point source of 1 candela." [NIST:NIST]
lm
lumen based unit
lumen
"A luminous flux unit which is equal to the luminous flux emitted into 1 steradian by a point source of 1 candela." [NIST:NIST]
lm