Alexandru Dan Toma
Full Text PDF | pyranometer , sun photometer, pyrheliometers , thermopile, silicon-based solar cell, LED.

The Sun's energy is distributed over a broad range of the electromagnetic spectrum and Sun behaves approximately like a "blackbody" radiating at a temperature of about 5800 K with maximum output in the green-yellow part of the visible spectrum, around 500 nm. Not all solar radiation reaching the top of the atmosphere reaches Earth's surface due to a various optical phenomena in regard to solar radiation crossing the Earth’s atmosphere. In order to investigate them, there are two general categories of instruments used to measure the transmission of solar radiation through Earth's atmosphere: instruments that measure radiation from the entire sky and instruments that measure only direct solar radiation. Within each of these categories, instruments can be further subdivided into those that measure radiation over a broad range of wavelengths and those that measure only specific wavelengths.

Current Trends in Natural Sciences

ISSN (online) 2284-953X
ISSN (CD-ROM) 2284-9521
ISSN-L 2284-9521
Publisher University of Pitesti, EUP