candela per meter squaredThe candela per meter squared (cd / m 2 ) is the standard unit of luminance. It represents a luminous intensity of one candela radiating from a surface whose area is one square meter. Formally, the candela is defined as the magnitude of an electromagnetic field ( EM field ), in a specified direction, that has a power level of 1/683 watt (1.46 x 10 -3 W) per steradian at a frequency of 540 terahertz (540 THz or 5.40 x 10 14 Hz). This is in the middle of the visible-light spectrum. Luminance is sometimes quoted when specifying the brightness of computer displays. Cathode-ray tube ( CRT ) monitors generally provide greater luminance than thin-film transistor ( TFT ) displays. However, the best criterion for choosing and adjusting a display is the user's own viewing comfort. This will depend on the level of illumination in the room where the display is used. Also see candela , meter squared , steradian , and SI (International System of Units).
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Sep 21, 2005 |
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Are you a Know-IT-All? What do you call the unused portions of the radio frequency spectrum? a. white space b. surplus space Answer
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