Typical solar spectrum Irradiance measurement applications include scientific meteorological/climate observations, material testing research, solar collector/Photo Voltaic panel efficiency and solar renewable resource assessment.
Sunlight is defined as the total spectrum of the electromagnetic radiation emitted by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is visible as daylight when the Sun is above the horizon. When the direct radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and heat. Sunlight may be recorded using a pyranometer, pyrheliometer or the AvaSolar system as described below. In the AvaSolar setup configuration we have a total of 4 channels, 2 x an identical setup for 200-2500nm. One spectrometer setup measures the direct sun radiation through a CC-UV/VIS/NIR-5.0 special cone cosine corrector with 5 degrees opening angle (see section Fiber Optics - Cosine correctors page 104). This 5 degree Cosine corrector is normally connected to a sun-tracker system.The other spectrometer setup measured with a standard CC-VIS/NIR cosine corrector and measures the total radiation. Typical Solar irradiance spectrum measured by a dual channel broad band AvaSpec-UV/VIS/NIR.
More info on about solar measurement in this application note