solskinnsregistratorer

Solskinnsregistratorer, also known as sunshine recorders, are instruments used to measure the duration of bright sunshine. These devices work by focusing sunlight onto a special paper or other medium, which then burns or discolors in proportion to the intensity and duration of the sunlight. The resulting mark on the paper serves as a record of sunshine hours.

The most common type of solskinnsregistrator is the Campbell-Stokes sunshine recorder. This instrument consists of a glass sphere mounted on a base. The sphere acts as a lens, concentrating sunlight onto a card placed in a groove on the base. As the sun moves across the sky, the focused beam traces a path on the card, burning a line. The length of this burned line is directly proportional to the amount of bright sunshine recorded for that day. Different types of cards are used for different seasons to accommodate the sun's varying altitude.

Another type is the Jordan sunshine recorder, which uses a series of small lenses to focus sunlight onto a rotating drum covered in photographic paper. While less common today, it represented an earlier approach to recording sunshine.

Solskinnsregistratorer are valuable tools in meteorology and climatology. They provide historical data on sunshine duration, which can be used for various applications, including agricultural planning, solar energy assessment, and understanding local climate patterns. While more sophisticated electronic instruments exist for measuring solar radiation, the simplicity and longevity of the burn-line recorders have ensured their continued use in many meteorological stations around the world. They offer a straightforward and visual representation of sunshine.