LUMEN

Lumen

The lumen is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements indicate the total power of all electromagnetic waves emitted, independent of the eye's ability to perceive it. A lux is one lumen per square meter.

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lumen

Noun

  1. 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.
  2. The cavity or channel within a tube or tubular organ.
  3. The cavity bounded by a plant cell wall.
  4. The bore of a tube such as a hollow needle or catheter.


The above text is a snippet from Wiktionary: lumen
and as such is available under the Creative Commons Attribution/Share-Alike License.

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