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Evaporation device for estimating irrigation
needs
A much cheaper device
than a weather station.
EtGage Model A Test
Results:
Tests run in various
locations (including Silsoe in the UK) since 1988 have shown
good agreement with other more expensive ways of measuring
ET. The graphs available show a good comparison of the ETGage
and two other methods, the Penman equation (using measurements
of humidity, temperature, wind, and solar radiation), and
a Bowen Ratio Station (a research method that measures the
flow of vapor from a crop).
The test shows close
agreement in a corn crop from July 4 to first freeze at the
USDA experiment station in Fort Collins, Colorado. Other data
available on request.
ETGage Model A, displayed
above, requires distilled water (available at food stores).
Components of the
system include:
1. Diffusion covers for grass ET (ETo) and crop ET (ETr).
2. Glass sight tube (inches and mm).
3. Stainless steel mounting bracket.
4. Instructions, irrigation management information and tables.
Purpose:
ETGage is an instrument
and method for viewing crop water use. It shows how much water
has been used by ET (evapotranspiration).
Use it for field
crops, turf and landscaping.
How It Works: ·
A ceramic evaporator
at the top of the instrument responds to sun and weather as
plants do. Water is drawn from a reservoir. · The water level
falls in the sight tube one mm for each mm used by your plants.
· Replaceable green canvas covers modify the evaporation rate
to simulate ET from field crops or grass. · Rain cannot get
into the instrument. · A rain gauge, situated with the ETGauge,
lets you measure rain separately.
Applications:
Irrigation scheduling.
Conservation of water, energy, fertilizer, topsoil and labor
through better management .
Non-point source pollution studies.
ETGage is used by
turf managers, irrigation consultants, farmers, and government
agricultural personnel in 37 US states and 23 countries. Inquire
about our electronic
ETGage Model E for
use with data loggers, counters and controllers.
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