Abstract: | The feasibility of using a potassium ferioxalate actinometer as a photochemical pyranometer was studied. The preparation, exposure, and spectrophotometric analysis of the pyranometer cell are described. By calibrating it against a Yellot Mark IV solameter, linear correlations were obtained with respect to total insolation and time of exposure. The spectral response, the quantum yields at different wavelengths, the mechanism of photochemical reaction, and the conversion factor for converting the absorption reading into cal/cm2/min are discussed. The advantages of the new pyranometer are its low cost, simplicity of operation and calibration, high sensitivity, and high tolerance to field conditions. It is useful for mapping solar intensity distribution over a wide area. |