Schelt Technology

PSR-01 is an affordable Shadow Ring for measuring thediffuse solar radiation with pyranometer. When properlyinstalled and routinely adjusted, the Shadow-Ring obstructsthe daily direct beam solar component from irradiating theradiometer mounted within the shadow-ring, from sunriseto sunset. Mechanical adjustment of the Shadow Ring isrecommended every two days for optimal measurementperformance. The resulting measurement when optionedwith a class 1 Pyranometer is representative of the totalglobal diffuse short-wave irradiance signal in W/m2.Because the shadow-ring obstructs a portion of the diffusesky 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 asecond non-shaded Pyranometer, it is possible to infer directbeam solar disk irradiance by subtracting the correctedshaded Pyranometer diffuse irradiance values from thenonshaded Pyranometer global solar irradiance values, forthe same time indices sampled.The Shadow Ring provides a reliable cost effective solutionfor deriving the constitute global short-wave diffuse anddirect beam solar irradiance components, in contrast toauto-tracking radiometer instrument solutions costingthousands more.