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Rain measurement: Difference between revisions
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→Rain Gauge Location: added quote on rim height from support forum
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The exposure of a rain gauge is very important for obtaining accurate measurements. As a general rule, the windier the gauge location is, the greater the precipitation error will be.
Gauges should not be located close to isolated obstructions such as trees or buildings, which may deflect precipitation due to erratic turbulence. To avoid wind and resulting turbulence problems, do not locate gauges in wide-open spaces or on elevated sites, such as the tops of buildings.
The WMO recommend that a rain gauge be placed away from any nearby obstacle a distance of at least twice the height of the obstacle. The best site for a gauge is one in which it is protected in all directions, such as in an opening in a grove of trees. The height of the protection should not exceed twice its distance from the gauge.▼
The standard height for the rim of a rain gauge varies by country. In the UK it is 30cm above ground. In the US it is between 3 and 4 feet. The placement is a compromise; lower placement reduces loss due to wind which may occur at higher levels, but increases the chance of heavy rain splashing in off the ground, and of being buried by snow, where applicable.
▲The best site for a gauge is one in which it is protected in all directions, such as in an opening in a grove of trees. The height of the protection should not exceed twice its distance from the gauge.
=Rain Rate=
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