The use of the Bellani Spherical Pyranometer for the measurement of total solar radiation

Abstract

The measurement of the total short-wave radiation falling from the sun, the sky and the surroundings on freely exposed objects, such as a plant, is of special interest in biology, bioclimatology and agricultural meteorology since radiation plays an im-portant part in controlling the growth features and physiological processes in plants like photosynthesis, photoperiod-ism etc. There are several instruments for the measurement of solar radiation. However, for use at agricultural farms, the important prerequisites of an instru-ment are simplicity of operation and main-tenance, low cost and acceptable accuracy. The commonly used instruments for the measurement of solar radiation at radiation stations are the Angstrom pyrheliometer for the measurement of instantaneous values and the Moll-Gorczynski solarimeter, the Eppley pyrbeliometer, Robitzsch bime-tallic actinograph and the Bellani spherical pyranometer for the measurement of in-tegrated values of radiation.