Analyses of the behavior of a bimetallic Actinograph (R. Fuess-Brlin-Steglitz) in different types of sky covering - DOI: 10.4025/actasciagron.v26i4.1800

Abstract

Part of the thermodynamic processes that occur in the development of the plants is related to the balance of the solar radiation in the atmosphere. For several years in Brazil, the global solar radiation has been being monitored by actinographs, with some researchers doubting the reliability of these data, comparing the sensor of this instrument, that is constituted by bimetallic plate, with one of the piranometer, elaborated with termopile. In this work, the measures of the global solar radiation are compared, monitored by actinography, and by a piranometer of Kipp and Zonen (I model CM3), instrument of larger precision, in different conditions of sky covering. The data were collected in the Experimental Station Agrometeorologic of the State University of the West of Paraná - Campus of Cascavel (lat. 24º 53`South, long. 53º 23`West, alt. 682m), in the period of January to December, 2001. The found deviations were 18.95% in days of clean sky, 15.78% in days of partially cloudy sky, 4.50% in days of cloudy sky and 15.11% without considering the type of sky covering, showing that the solar irradiation obtained by the actinograph is underestimated independent of the conditions of sky covering