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Evapotranspiration, or ET, is a measurement of the water that evaporates into the air from the
soil and the amount of water that is used (transpired) by a plant. ET is used to determine how
much water must be returned to the landscape either by rainfall or by using your sprinkler
system.
How Weather Reach Works
With the understanding of these basic principles, let’s discover how Weather Reach works. To
begin, Weather Reach receives a signal from a weather station located near your landscape.
Weather data including solar energy, temperature, wind, humidity, and rainfall, is broadcast from
the Weather Reach Service Provider every hour from the weather station directly to your
Weather Reach Receiver (see the figure below). The Weather Reach Receiver uses this data to
compute ET and control how often your sprinkler controller waters your landscape.
This graph illustrates that ET is highest in the hot summer months, exactly the time when your
lawn needs the most water.
ET for One Year
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