Printer Friendly
The Free Dictionary
1,075,921,590 visitors served.
?
Dictionary/
thesaurus
Medical
dictionary
Legal
dictionary
Financial
dictionary
Acronyms
 
Idioms
Encyclopedia
Wikipedia
encyclopedia
?

lumen
(redirected from lumenal)

   Also found in: Dictionary/thesaurus, Medical, Wikipedia, Hutchinson 0.01 sec.
lumen: see photometry photometry (fōtŏm`ətrē)
..... Click the link for more information.
.

A unit of measurement of the amount of brightness that comes 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 13 lumens; a 100 watt bulb generates 1,200 lumens.

Lumen Ratings for Data Projectors
When choosing a data projector, the lumen rating is an important specification. In a darkened room, 500 lumens may be ample; however, in a conference room with normal lighting, 1,000 lumens would be better. In a room with daylight, 2,000 lumens is preferred. The standard lumen rating of a data projector is the average of photometer readings at several points on a full white image on the screen. See ANSI lumen, candela and spectrum.



How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content.
?Page tools
Printer friendly
Cite / link
Email
Feedback
? Mentioned in ? References in periodicals archive
 
Many of the airways from Mexico City also showed lumenal distortion (Figure 1C).
Light microscopy showed a well developed neointima lining the anastomotic region of the graft without apparent lumenal reduction.
Instead, evidence suggests that denervation leads to an "up-regulation" of muscarinic receptors that promotes increased calcium influx in the coronary arteries of the transplanted heart, facilitating a more insidious, diffuse, circumferential narrowing of arterial lumenal diameters.
 
Encyclopedia browser? ? Full browser
 
 
Encyclopedia
?

Disclaimer | Privacy policy | Feedback | Copyright © 2008 Farlex, Inc.
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.. Terms of Use.