The important of solar energy as a pure radiation free of pollutant, a multiple wavelength radiometer mainz designed for the purpose of measuring atmospheric turbidity collecting maximum radiation per unit area, & extinction coefficient of solar radiation by aerosol at discrete wavelengths through the visible region to near IR region is described in Global Atmospheric Watch station mountain. These techniques apply for conditions where the optical depth is either temporally variant or invariant during the course of day. The influence of the aerosol size distribution on optical is investigated. Method is presented for estimating the diurnal variation & the monthly variation of the mean atmospheric turbidity during 2007-2008 from multi wavelength depth measurements. However, for such site of clean air our measurements show there is fall of solar energy at the rate of 9´103 calories per day.
