The light from this candle is measured in lumens.
An example of a lumen is the 13 lumens of a candle and the 1,200 lumens of a 100 watt light bulb.
- the basic unit used to measure the flow of light in the SI system, equal to the amount of light emitted through a solid angle of one steradian by a light source with the intensity of one candela (0.0015 watt): abbrev. lm
- the bore of a hollow needle, catheter, etc.
- Anat. the passage within a tubular organ
Origin of lumenModern Latin ; from L, light
nounpl. lu·mens or lu·mi·na
- Anatomy The inner open space or cavity of a tubular organ, as of a blood vessel or an intestine.
- Biology The interior of a membrane-bound compartment or organelle in a cell.
- Abbr. lm Physics The SI unit of luminous flux, equal to the amount of light per unit time passing through a solid angle of one steradian from a light source of one candela intensity radiating equally in all directions. See Table at measurement.
Origin of lumenLatin l&umacron;men, an opening, light; see leuk- in Indo-European roots.
- lu′men·al, lu′min·al
(plural lumens or lumina)
- (physics) In the International System of Units, the derived unit of luminous flux; the light that is emitted in a solid angle of one steradian from a source of one candela. Symbol: lm.
- (anatomy) The cavity or channel within a tube or tubular organ.
- (botany) The cavity bounded by a plant cell wall.
- (medicine) The bore of a tube such as a hollow needle or catheter.
lumen - Computer Definition
A unit of measurement of the light intensity radiating in the air in all directions from a light source. Lumens define "luminous flux," which is energy within the range of frequencies we perceive as light. For example, a wax candle generates about 13 lumens; a 60-watt bulb approximately 800, and a 100-watt bulb 1,600 lumens. Lumen Ratings for Data Projectors When choosing a data projector, the lumen rating is an important specification. In a small, dark room, 500 lumens may be ample; however, in a conference room with normal lighting, 1,000 to 2,000 lumens is required. In a large, well-lit room, at least 2,000 lumens is necessary. This rating is derived by taking the average of photometer readings at several points on a full white image on the screen. See lux, ANSI lumen, Lm/W, candela and spectrum.