Radiant Intensity

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radiant intensity

[′rād·ē·ənt in′ten·səd·ē]
The energy emitted per unit time per unit solid angle about the direction considered; usually expressed in watts per steradian.

Radiant Intensity


a radiometric unit that characterizes the radiation from a source in a certain direction. Radiant intensity is equal to the ratio of the radiant flux emitted by the source in an infinitesimal solid angle containing the direction considered to the solid angle. The concept of radiant intensity is applicable at distances from the source that greatly exceed the source’s dimensions. The unit of radiant intensity is watts per steradian.

References in periodicals archive ?
* A typical radiant intensity of 650 mW/sr at a DC current of 1 A (4232).
However, this necessitates an accurate prediction of the radiant intensity field.
The first term represents the spectral emission from the surface, while the second term represents the reflected radiant intensity. Note that for a room with a glazing system, the boundary conditions need to be modified to incorporate the transmission through the window.
(1997), considers discrete directions and nodes and calculates the radiant intensity at each point and direction within the enclosure.
While standard IR emitters typically offer drive currents to 100 mA, the low thermal resistivity of the VSLB9530S allows continuous drive currents up to 150 mA, which pushes the achievable radiant intensity to 60 mW/sr at 150 mA.
The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 X [10.sup.12] hertz and that has a radiant intensity in that direction of 1/683 watts per steradian.
20 is related to the radiant intensity of the beam per milliamperes of beam current.
The instrument is suitable for luminous or radiant intensity measurements, tunnel brightness, total luminous or radiant flux measurements, device brightness, signal brightness, and equipment and device illumination measurements.
The company's processing technique accommodates fabrication of pixels 25 microns square with radiant intensity of 25 [micro]W to 75 [micro]W per steradian at 3 mA depending on wavelength.