The 96d Campbell-Stokes Pattern Sunshine Recorder employs a glass sphere to focus the sun’s rays to an intense spot, which will char a mark on a curved card mounted concentrically with the sphere.
Campbell-Stokes Sunshine Recorder
Description
The 96d Campbell-Stokes Pattern Sunshine Recorder employs a glass sphere to focus the sun’s rays to an intense spot, which will char a mark on a curved card mounted concentrically with the sphere. As the earth rotates, the position of the spot moves across the card. When the sun is obscured, the trace is interrupted. At the end of the day the total length of the trace, less gaps, is proportional to the duration of sunshine.
This instrument is manufactured to a proven design and is of the type used extensively by meteorological services world wide. In 1964 this design was adopted by the World Meteorological Organisation as their Interim Reference Recorder for use in all member countries.
