When properly installed and routinely adjusted, the  Shadow-Ring obstructs the daily direct beam solar component from irradiating the radiometer mounted within the shadow-ring, from sunrise to sunset. Mechanical adjustment of the Shadow Ring is recommended every two days for optimal measurement performance.The resulting measurement when optioned with a class  1 pyranometer is representative of the total global diffuse short-wave irradiance signal in W/m. Because the shadow-ring obstructs a portion of the diffuse sky field measured by the pyranometer, it is recommended to apply a small multiplier correction to account for the sky-field obstruction in the calculated diffuse irradiance measurement results. When used in conjunction with a second non-shaded  pyranometer, it is possible to infer direct beam solar disk irradiance by subtracting the corrected shaded pyranometer diffuse irradiance values from the non-shaded pyranometer global solar irradiance values, for the same time indices sampled.The Shadow Ring  provides a reliable cost effective solution for deriving the constitute global short-wave diffuse and direct beam solar irradiance components, in contrast to auto-tracking radiometer instrument solutions costing thousands more.

• auto-tracking radiometer instrument solutions costing thousands