Information AboutIrradiance |
| CATEGORIES ABOUT IRRADIANCE | |
| physical quantity | |
| radiometry | |
| SHOPPER'S DELIGHT | |
|
All of these quantities characterize the total amount of radiation present, at all frequencies. It is also common to consider each frequency in the spectrum separately. When this is done for radiation incident on a surface, it is called spectral irradiance, and has SI units W/m3, or commonly W·m-2·nm-1. If a point source radiates light uniformly in all directions and there is no absorption, then the irradiance drops off in proportion to the distance from the object squared, since the total power is constant and it is spread over an area that increases with the square of the distance from the source. SEE ALSO |