What is a Campbell-Stokes recorder used for?
Sunshine is recorded with a simple, yet clever device, called a Campbell-Stokes recorder, the design of which goes back to 1879. In this device a glass sphere concentrates sunlight onto a card and the amount of scorching on the card records the amount of sunlight that had fallen on it.
What unit does a Campbell-Stokes recorder measure?
The Casella Campbell Stokes Sunshine Recorder is manufactured to a design based on British Meteorological Office (BMO) specifications. It is designed to measure the duration of visible sunshine for one day and uses the intensity of the Sun’s rays to burn a trace on to a recording card.
What is the unit of sunshine recorder?
The physical quantity of sunshine duration (SD) is, evidently, time. The units used are seconds or hours.
How does a Campbell sunshine recorder work?
A Campbell-Stokes sunshine recorder concentrates sunlight through a glass sphere onto a recording card placed at its focal point. The length of the burn trace left on the card represents the sunshine duration. The focus shifts as the sun moves, and a burn trace is left on the recording card at the focal point.
What does a Stevenson screen measure?
Stevenson screens may also be known as a cotton region shelter, an instrument shelter, a thermometer shelter, a thermoscreen, or a thermometer screen. Its purpose is to provide a standardised environment in which to measure temperature, humidity, dewpoint, and atmospheric pressure.
How do you measure sunshine hours?
Sunshine is measured using either Campbell-Stokes sunshine recorders or modern sunshine sensors. A pyranometer is used for measuring global radiation.
Where is a sunshine recorder placed at a weather station?
It is important to place the unit in an area where the sun will not be blocked by buildings, trees or flagpoles. A modification to the standard unit for polar regions is the addition of a second, north facing, sphere and card, to record the sunlight during the summer when it remains in the sky for 24 hours.
What is the other name of sunshine recorder?
Sunshine recorders are sometimes called “heliographs,” but this can lead to confusion with the signaling devices of the same name, which are unrelated. The most widespread variety was invented in 1853 by the John Francis Campbell (Iain Òg Ìle).
When long curved cards are used in sunshine recorder?
The short curved are used for winter season, long curved card for summer season and straight cards in equinoxes are used. This is a type of time scale used to measure the length of burn to obtain the duration of sunshine.
What is the importance of sunshine recorder?
A sunshine recorder is a device that records the amount of sunshine at a given location or region at any time. The results provide information about the weather and climate as well as the temperature of a geographical area. This information is useful in meteorology, science, agriculture, tourism, and other fields.
Where should a sunshine recorder be placed?