luminous intensity


luminous intensity
the luminous flux in lumens emitted per unit solid angle by a light source, measured in candles.

* * *

      the quantity of visible light that is emitted in unit time per unit solid angle. The unit for the quantity of light flowing from a source in any one second (the luminous power, or luminous flux) is called the lumen. The lumen is evaluated with reference to visual sensation. The sensitivity of the human eye is greatest for light having a wavelength of 555 nanometres (10-9 metre); at this wavelength there are 685 lumens per watt of radiant power, or radiant flux (the luminous efficiency), whereas at other wavelengths the luminous efficiency is less. The unit of luminous intensity is one lumen per steradian, which is the unit of solid angle—there are 4π steradians about a point enclosed by a spherical surface. This unit of luminous intensity is also called the standard candle, or candela, one lumen per steradian.

* * *


Universalium. 2010.

Look at other dictionaries:

  • luminous intensity — n the intensity of a light source as measured by the luminous flux per unit solid angle and usu. expressed in candles * * * the light giving power of a source of light. Cf. candle power …   Medical dictionary

  • Luminous intensity — In photometry, luminous intensity is a measure of the wavelength weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye.… …   Wikipedia

  • luminous intensity — noun : a quantity used to specify the light giving power of a source (as a lamp) and usually expressed in candles a point source whose luminous intensity is one candle emits one lumen of luminous flux per steradian of solid angle * * * Optics.… …   Useful english dictionary

  • luminous intensity — šviesos stipris statusas T sritis automatika atitikmenys: angl. light intensity; luminous intensity vok. Lichtintensität, f; Lichtstärke, f rus. интенсивность света, f pranc. intensité de la lumière, f; intensité lumineuse, f …   Automatikos terminų žodynas

  • luminous intensity — šviesos stipris statusas T sritis Standartizacija ir metrologija apibrėžtis Vienas pagrindinių SI dydžių, apibūdinantis regimosios šviesos šaltinio švytėjimą kuria nors kryptimi. Jis išreiškiamas šviesos srauto ir erdvinio kampo, kuriame sklinda… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • luminous intensity — /lumənəs ɪnˈtɛnsəti/ (say loohmuhnuhs in tensuhtee) noun (of a point source of light) the luminous flux emitted per unit solid angle, measured in candela …   Australian English dictionary

  • luminous intensity — noun A measure of the power emitted by a source of light; equal to the flux density per solid angle …   Wiktionary

  • Luminous intensity — Сила света (в канделах) …   Краткий толковый словарь по полиграфии

  • luminous intensity — Смотри сила света …   Энциклопедический словарь по металлургии

  • luminous intensity standard — šviesos stiprio etalonas statusas T sritis fizika atitikmenys: angl. luminous intensity standard; luminous standard; standard of light intensity vok. Lichtstärkenormal, n rus. эталон силы света, m pranc. étalon de l’intensité lumineuse, m …   Fizikos terminų žodynas


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.