Casella Model 6100 Mark IIIA Tropical Campbell Stokes Sunshine Recorder
Front View
Right View
Left View
This is another Model 6100 Campbell Stokes Sunshine Recorder made by Casella of Great Britain.
This particular instrument is Meteorological Office Pattern Mark IIIA and was designed to be used in tropical latitudes. It differs in appearance from the temperate model also on this website primarily in the shape of the chart bowl. The Casella catalog indicates that it is usable from 0 to 40 degrees latitude (north or south). The adjustable latitude scale on the instrument ranges from 0 to 65 degrees and was probably used on various models.. The instrument is exposed by pointing it due south (in the Northern Hemisphere). A time calibrated heat-sensitive strip is placed in the curved chart holder, one per day of recording, and the refracted beam of sunlight burns a record in the strip of the duration of sunshine. This particular example has an attached plaque that says Avon Park, Florida, which is 27.6 degrees N latitude.
Model 6100 is shown in the 1958 and 1963 Casella catalogs on this website, but not in the 1948 catalog. So this instrument probably dates from the 1950s or newer. The glass sphere is 4 inches in diameter. The entire instrument weighs about 12 pounds.
This particular instrument is Meteorological Office Pattern Mark IIIA and was designed to be used in tropical latitudes. It differs in appearance from the temperate model also on this website primarily in the shape of the chart bowl. The Casella catalog indicates that it is usable from 0 to 40 degrees latitude (north or south). The adjustable latitude scale on the instrument ranges from 0 to 65 degrees and was probably used on various models.. The instrument is exposed by pointing it due south (in the Northern Hemisphere). A time calibrated heat-sensitive strip is placed in the curved chart holder, one per day of recording, and the refracted beam of sunlight burns a record in the strip of the duration of sunshine. This particular example has an attached plaque that says Avon Park, Florida, which is 27.6 degrees N latitude.
Model 6100 is shown in the 1958 and 1963 Casella catalogs on this website, but not in the 1948 catalog. So this instrument probably dates from the 1950s or newer. The glass sphere is 4 inches in diameter. The entire instrument weighs about 12 pounds.
An instruction sheet for the Casella Campbell Stokes Sunshine Recorder may be downloaded below (2 pages):
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