luminous intensity

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lu·mi·nous in·ten·si·ty (I),

the luminous flux per unit solid angle in a given direction.

lu·mi·nous in·ten·si·ty

(I) (lū'mi-nŭs in-ten'si-tē)
The luminous flux per unit solid angle in a given direction.
Synonym(s): radiant intensity.

intensity, luminous

Quotient of the luminous flux leaving the source, propagated in an element of solid angle containing the given direction, divided by the element of solid angle. Symbol: I. Unit: candela (CIE).
References in periodicals archive ?
[I.sub.[lambda]]([OMEGA]) = directional spectral radiant intensity (W/[m.sup.2] x sr x [micro]m)
[I.sub.b,[lambda]] = spectral radiant intensity for a black body (W/[m.sup.2] x sr x [micro]m)
[I.sub.bndx,[lambda]] = total spectral radiant intensity at boundary in the x direction (W/[m.sup.2] x sr x [micro]m)
[I.sub.bndy,[lambda]] = total spectral radiant intensity at boundary in the y direction (W/[m.sup.2] x sr x [micro]m)
[I.sub.bndz,[lambda]] = total spectral radiant intensity at boundary in the z direction (W/[m.sup.2] x sr x [micro]m)
[I.sub.[lambda]] = total spectral radiant intensity (W/[m.sup.2] x sr x [micro]m)
[I.sup.j] = Total Radiant Intensity in discrete direction (W/[m.sup.2] x sr x [micro]m)
[I.sub.p.sup.j] = total radiant intensity in discrete direction j for pth control volume (p varies from 1 to total number of control volumes) (W/[m.sup.2] x sr x [micro]m)
Theory indicates that if the magnetic field, radius of the orbit, and electron current are known, then the absolute radiant intensity of the beam can be calculated.
When integrated spectrally using V ([lambda]) weighting, one obtains the photometric counterpart, on the right Radiometric quantity Symbol Unit Unit Radiant energy Q J lm s Radiant flux (power) P, [PHI] W lm Irradiance E W/[m.sup.2] lm/[m.sup.2]=lx Radiance L W/([m.sup.2] sr) lm/([m.sup.2] sr) Radiant intensity I W/sr lm/sr=cd Radiometric quantity Symbol Photometric quantity Radiant energy [Q.sub.v] Luminous energy Radiant flux (power) [[PHI].sub.v] Luminous flux Irradiance [E.sub.v] Illuminance Radiance [L.sub.v] Luminance Radiant intensity [I.sub.v] Luminous intensity J=joule, lm=lumen, s=second, W=watt, m=meter, sr=steradian, cd=candela.