Evapotranspiration (Et); Leaf Wetness; Soil Moisture; Time - DAVIS Weather Envoy 6314 Installation Manual

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Table Of Contents

Table of Contents

Ev a p o Tr a n s p i r a t i o n ( E T )

Note: Requires optional solar radiation sensor (#6450, included on Vantage Pro Plus

weather stations).

EvapoTranspiration (ET) is a measurement of the amount of water vapor returned

to the air in a given area. It combines the amount of water vapor returned through

evaporation (from wet vegetation surfaces and the stoma of leaves) with the

amount of water vapor returned through transpiration (exhaling of moisture

through plant skin) to arrive at a total. Effectively, ETo is the opposite of rainfall,

and it is expressed in the same units of measure (Inches, millimeters).

The Weather Envoy uses air temperature, relative humidity, average wind speed,

and solar radiation data to estimate ET. (ET is calculated once an hour on the

hour.)

Please note that calculating ET requires the optional solar radiation sensor.

Leaf Wetn ess

Note: Leaf Wetness is only available with the wireless Weather Envoy using the optional

Leaf and Soil Moisture/Temperature station (#6343) with a Leaf Wetness sensor

(#6420).

Leaf wetness provides an indication of whether the surface of foliage in the area

of the sensor is wet or dry by indicating how wet the surface of the sensor is. The

leaf wetness reading ranges from 0 (dry) to 15.

Soi l M o i s t u r e

Note: Soil Moisture is only available with the wireless Weather Envoy using the optional

Leaf and Soil Moisture/Temperature station (#6343) with a Soil Moisture sensor

(#6440).

Soil Moisture, as the name suggests, is a measure of the moisture content of the

soil. Soil moisture is measured on a scale of 0 to 200 centibars, and can help choose

times to water crops. The soil moisture sensor measures the vacuum created in the

soil by the lack of moisture. A high soil moisture reading indicates dryer soil; a

lower soil moisture reading means wetter soil.

Ti m e

The Weather Envoy has a clock and a calendar for tracking time and date. The

calendar automatically adjusts during leap years and daylight savings, providing

you have entered the correct year, lattitude and longitude, and daylight savings

settings in the Setup Mode.

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