
	Where results make sense

Topic: Luminous emittance

In the News (Wed 30 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	AWI: Transfer of Technology: Ring light
		The direction of emittance of the light source is perpendicular to the axis of the hollow cylinder toward the inside and therefore is aligned to correspond to radial planes oriented orthogonally to the axis of the hollow cylinder.
		The emittance of the luminous means of the light source must be focused into a horizontal beam path that is strictly limited with regard to the length of the hollow cylinder.
		When using LEDs as the luminous means in the light source, they may be arranged with their longitudinal axis directly in the direction of emittance of light, i.e., perpendicular to the axis of the hollow cylinder forming the light source.
	www.awi-bremerhaven.de /TT/ringleuchte/index-e.html (1292 words)

	Luminous Flux Density \| Illuminance \| Illumination \| Lux \| Luminous Exitance \| Luminous Emittance
		Luminous emittance is a deprecated term for Luminous Exitance.
		Luminous flux density is photometrically weighted radiant flux density, which means luminous flux per unit area at a point on a surface where the surface can be real or imaginary.
		Luminous exitance or is the total amount of visible light leaving a point on a surface into all directions above the surface.
	www.schorsch.com /kbase/glossary/illuminance.html (228 words)

	Luminous flux - Wikipedia, the free encyclopedia
		The SI unit of luminous flux is the lumen (lm).
		One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one steradian.
		Luminous flux is often used as an objective measure of the useful power emitted by a light source, and is typically reported on the packaging for light bulbs, although it is not always prominent.
	en.wikipedia.org /wiki/Luminous_flux (430 words)

	Luminous efficacy - Wikipedia, the free encyclopedia (Site not responding. Last check: )
		Luminous efficacy is the ratio of the total apparent power of a light source to its actual total power.
		Luminous efficacy measures the fraction of power which is useful for lighting.
		This is because it equals luminous flux/radiant flux.
	www.dictionpedia.com /en/Luminous_efficacy (210 words)

	Luminous intensity - Wikipedia, the free encyclopedia
		Luminous intensity should not be confused with another photometric unit, luminous flux, which is the total perceived power emitted in all directions.
		Luminous intensity is also not the same as the radiant intensity, the corresponding objective physical quantity used in the measurement science of radiometry.
		In 1881, Jules Violle proposed the Violle as a unit of luminous intensity, and it was notable as the first unit of light intensity that did not depend on the properties of a particular lamp.
	en.wikipedia.org /wiki/Luminous_intensity (371 words)

	FLATNET Technical Glossary (Site not responding. Last check: )
		Luminous flux emitted by a point source (or surface element of an extended source) into an infinitesimal cone containing the given direction, divided by the solid angle of that cone.
		Luminance at a point on a surface and in a given direction is the luminous intensity in the given direction of an infinitesimal surface element containing the point under consideration, divided by the area of the orthogonal projection of this surface element on a plane perpendicular to the given direction.
		Luminous emittance at a point on a surface is the luminous flux emitted by an infinitesimal surface element containing the point, divided by the area of the surface element.
	flatnet.phy.cam.ac.uk /glossary/photometry.htm (164 words)

	Dictionary of Technical Terms for Aerospace Use - L (Site not responding. Last check: )
		In photometry, a modifier used to denote that a given physical quantity, such a luminous emittance, is weighted according to the manner in which the response of the human eye varies with the wavelength of the light.
		The instantaneous amount of luminous energy contained in a unit volume of the propagating medium; to be distinguished from radiant density in that it is weighted in accordance with the characteristics of the human eye in its nonuniform response to different wavelengths of light.
		Luminous energy per unit time per unit solid angle; the intensity (flux per unit solid angle) of visible radiation weighted to take into account the variable response of the human eye as a function of the wavelength of light; usually expressed in candles.
	roland.grc.nasa.gov /~dglover/dictionary/l.html (7224 words)

	Lm (Site not responding. Last check: )
		The lumen (symbol: lm) is the SI unit of luminous flux.
		One lumen is the luminous flux emitted by a light source that puts out one candela of luminous intensity over a solid angle of one steradian.
		ratio of luminous flux to radiant flux, maximum possible is 683
	www.donob.com /encyclopedia/Lm (103 words)

	Reference.com/Encyclopedia/Illuminance
		In photometry, illuminance is the total luminous flux incident on a surface, per unit area.
		It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with human brightness perception.
		Similarly, luminous emittance is the luminous flux per unit area emitted from a surface.
	www.reference.com /browse/wiki/Illuminance (264 words)

	Lux - Encyclopedia, History, Geography and Biography
		Lux is a derived unit based on lumen, and lumen is a derived unit based on candela.
		One lux is equal to one lumen per square metre, where 4π lumens is the total luminous flux of a light source of one candela of luminous intensity.
		The ratio between the actual number of lumens per watt and the theoretical maximum is expressed as a percentage known as the luminous efficiency.
	www.arikah.com /encyclopedia/Lux (911 words)

	Lm Information - Online Prescription Medication Directory (Site not responding. Last check: )
		The lumen (symbol: lm) is the SI unit of luminous flux, a measure of the perceived power of light.
		Luminous flux differs from radiant flux, the measure of the total power of light emitted, in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light.
		If a light source emits one candela of luminous intensity into a solid angle of one steradian, the total luminous flux emitted into that solid angle is one lumen.
	www.prescriptiondrug-info.com /drug_information_online.asp?title=Lm (309 words)

	Physics Tutoring: Electromagnetic Waves (Site not responding. Last check: )
		luminosity factor: The ratio of the luminous flux in lumens emitted by a source at a particular wavelength to the corresponding radian flux, in watts, at the same wavelength this is a measure of the visual sensitivity of the eye.
		luminous coefficient: A measure of the fraction of the radian power of a light source which contributes to its luminous properties, equal to the average of the luminosity function at various wavelengths, weighted according to the spectral intensity of the source.
		luminous intensity: The luminous flux incident on a small surface which lies in a specified direction from a light source and is normal to this direction, divided by the solid angle (in steradian) which the surface subtends at the source of light.
	www.slcc.edu /schools/hum_sci/physics/tutor/2220/em_waves (1034 words)

	AMS Glossary
		Luminance is obtained by integrating spectral radiance weighted by luminous efficiency over the visible spectrum.
		Luminous efficiency is dimensionless but is often given the units of lumens per watt.
		Photometric quantities are obtained by multiplying the corresponding radiometric quantities by the luminous efficiency and so often bear the adjective luminous, for example, luminous flux.
	amsglossary.allenpress.com /glossary/browse?s=l&p=36 (290 words)

	handprint : colormaking attributes
		Luminous flux can be calculated by measuring the output from a light source from many different angles at equal distances, then integrating these over a spherical area; or by measuring the reflected light at one point inside a diffusing sphere, and extrapolating that quantity to the total surface.
		However, luminous intensity is still a "source centric" or abstract measure of light, because we have not specified the distance to a viewer or illuminated surface, nor the size of a physical surface that receives the light.
		This is the anchor of luminance adaptation for two reasons: the luminance of surfaces is constant across distance (as with lights); and, for diffusely reflecting surfaces, luminance is not significantly affected by the angle of view or the angle of incident light.
	www.handprint.com /HP/WCL/color3.html (17377 words)

	Method and apparatus for active pyrometry - Patent 5029117
		The method of claim 1 wherein step (d) comprises measuring the sum of the light radiated by the wafer plus background luminous flux, measuring the background luminous flux when light from the wafer is obscured, and subtracting the background luminous flux from the sum of the light radiated by the wafer plus background luminous flux.
		Furthermore, the use of pyrometry techniques in the measurement of semiconductor wafer temperatures is complicated by the fact that the environment surrounding these wafers is frequently flooded with light from the radiative elements employed in heating and maintaining the temperature of the wafers during processing.
		This figure is then divided by the emittance previously calculated and further by a calibration constant C for the system 10 in order to generate a signal level corresponding to the fourth power of the temperature of the semiconductor wafer 12.
	www.freepatentsonline.com /5029117.html (3524 words)

	[No title] (Site not responding. Last check: )
		] The unit of luminous flux, equal to the luminous flux emitted within a unit solid angle (1 steradian) from a point source having a uniform intensity of 1 candela, or to the luminous flux received on a unit surface, all points of which are at a unit distance from such a source.
		] The ratio of luminous flux in lumens emitted by a source at a particular wavelength to the corresponding radiant flux in watts at the same wavelength; thus this is a measure of the visual sensitivity of the eye.
		] The luminous flux incident on a small surface which lies in a specified direction from a light source and is normal to this direction, divided by the solid angle (in steradians) which the surface subtends at the source of light.
	www.accessscience.com /Dictionary/L/L24/DictL24.html (1592 words)

	Piezo-optic measuring transducer and accelerometer, pressure gauge, dynamometer, and thermometer based thereon - Patent ...
		In this case, used as the means for varying the intensity of the luminous flux in the additional polarization-optical channel 15, which variation is opposite in polarity to that in the luminous flux through the main polarization-optical channel 14, are the polarizers 34, 35 and analyzers 38, 39.
		In a transducer whose polarizers and analyzers are not used as the means for varying the intensity of the luminous flux in the additional polarization-optical channel, which variation is opposite in polarity to that in the luminous flux through the main polarization-optical channel, their polarization planes in both channels may be parallel or mutually perpendicular.
		10, the function of the means for varying the intensity of the luminous flux in the polarization-optical channel 88, which variation is opposite in polarity to that in the intensity of the luminous flux in the polarization-optical channel 83, is performed by the elastic element 78 occurring wherein are strains having opposite signs.
	www.freepatentsonline.com /3950987.html (15159 words)

	Radiometry and Photometry
		The photometric equivalent of the radiant emittance M is the luminous emittance M, measured in lm/m
		The photometric equivalent of the radiant intensity I is the luminous intensity I. It is measured in lm/sr or candela.
		The luminance L is the property of a source that is commonly called "brightness".
	electron9.phys.utk.edu /optics421/modules/m4/radiometry.htm (1197 words)

	Photonics.com \| Search
		The result: a specified spectral luminous efficiency function V (λ) to...
		Luminous flux The fundamental quantity used in photometry is luminous flux, which is the visible...
		require the ability to calculate luminous intensity; that is, light intensity...
	www.photonics.com /photonicsFind.aspx?searchString=luminous&searchIndex=0 (418 words)

	illuminance \| English \| Dictionary & Translation by Babylon
		In photometry, illuminance is the total luminous flux incident on a surface, per unit area.
		It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with human brightness perception.
		Similarly, luminous emittance is the luminous flux per unit area emitted from a surface.
	www.babylon.com /definition/illuminance (103 words)

	PICOSECOND-RESOLUTION ‘SLICE’ EMITTANCE MEASUREMENT OF ELECTRON-BUNCHES
		In the emittance compensation technique, suggested by Bruce Carlsten [2], the observed emittance growth due to linear components of space charge forces in the photoinjector is compensated by passing the electron beam through a laminar-flow beam-waist.
		The measured normalized rms emittances of the three slices are 3.5 ± 1.1, 2.8 ± 1.1 and 2.3 ± 1.1 for the front, center and end of the bunch slices, respectively.
		This is an emittance compensated beam from the ATF photoinjector.
	www.bnl.gov /atf/publications/slice.htm (2955 words)

	Aerospace Science and Technology Dictionary L Page
		Physically, the lambert is the luminance of a perfectly diffusing white surface receiving an illuminance of 1 lumen per square centimeter.
		A law of physics which states that the radiant intensity (flux per unit solid angle) emitted in any direction from a unit radiating surface varies as the cosine of the angle between the normal to the surface and the direction of the radiation.
		The radiance (or luminance) of a radiating surface is, therefore, independent of direction.
	www.hq.nasa.gov /office/hqlibrary/aerospacedictionary/508/l.html (10422 words)

	Units of Light Measurement (Site not responding. Last check: )
		The illumination of light is the quantity, or luminous flux, of an area.
		In a set experiment of light output, luminous flux is defined as the flow rate of light energy, and an extra element called luminous intensity, expresses the concentration of light quantity in one direction, or one beam of light.
		The luminous flux released in that solid angle would be very small, but the luminous intensity has light emitted in a single direction.
	www.lumex.com /tech_notes/thery_3c.html (236 words)

	Fluorescent lamp (Site not responding. Last check: )
		The luminous efficacy of a fluorescent lamp changes according to the mercury-vapor pressure ratio of the lamp.
		Since the electrodes of fluorescent lamps generate heat, the cold spot temperature is influenced by the relative position of the electrodes with respect to the cold spot.
		If the temperature of the cold spot becomes too high, then the luminous flux decreases, because, the in excess evaporated mercury absorbs ultraviolet rays generated in the fluorescent lamp, which are changed to visible light.
	www.electronics-manufacturers.com /info/lightings-and-lamps/fluorescent-lamp.html (2462 words)

	Glossary E-L (Site not responding. Last check: )
		luminance at the given point in the various directions of the incident elementary beams of solid angle dΩ and is θ angle between any of these beams and the normal to the surface at the given point.
		Luminous flux emitted in unit solid angle (steradian) by a uniform point source having a luminous intensity of 1 cd.
		Luminous flux of a beam of monochromatic radiation whose frequency is 540 10
	learn.unl.ac.uk /%7Easia/website/glossary/glosetol.html (2374 words)

	Candela - Engineering
		The candela (symbol: cd) is the SI base unit of luminous intensity (perceived power emitted by a light source in a particular direction).
		The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540Template:E hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.
		The candela was based on an older unit, the candlepower, which was referenced to the luminous intensity of a "standard candle" of known composition.
	engineering.wikia.com /wiki/Candela (328 words)

	Bunch Spacing
		While the time between bunch crossings is 25 nsec at the LHC and the bunches are separated by 7.5 m, these numbers are 17 nsec and 5 m, respectively, for the VLHC.
		= 5 cm, the luminous region varies from 7 cm to 3 cm as the crossing angle is varied from 0 to 200 microradians.
		Going from a 1- cm luminous region to a 1-meter one does not change the detector size dramatically since typical calorimeter/magnet dimensions are several meters.
	vlhc.org /vlhc/tjef/bunch_spacing/bunch_spacing.html (1509 words)

Try your search on: Qwika (all wikis)