The 240-8104 Albedometer is essentially a combination of two star pyranometers, one facing upward and one facing downward. The upward facing pyranometer measures global radiation (diffuse and direct solar radiation), while the downward facing pyranometer measures reflected solar radiation. Separate outputs are provided for each pyranometer, which can be recorded together on a strip chart recorder. Albedo, the fraction of incident radiation reflected by a surface, can be calculated from the output data (albedo = reflected radiation ÷ global radiation). Short-wave net radiation can also be calculated.