EA-10 Soil Moisture Sensor Integrator’s Guide
3. How the EA-10 Works
10
(no air gaps). The soil must therefore be packed tightly
around the entire probe length during installation. The
probe is installed with the blade perpendicular to the
surface to interfere as little as possible with water
movement through the soil.
Calibration
The probe reading is converted to volumetric water
content using the following equation:
Volumetric Water Content = 0.0425 x Current - 0.342
Water content is in m
3
m
-3
, and current is in milli-
amps. For water content in terms of percent of total
volume, use the following equation:
Volume percent = 4.25 x Current - 34.2.
These calibrations are for typical soils with mid range
texture, and are accurate enough for most irrigation
scheduling purposes. For greater accuracy, a soil spe-
cific calibration should be undertaken, as outlined on
the Decagon website.
Functional Testing
ECH
2
O EA-10 sensors are tested to perform cor-
rectly in the following conditions:
Sensor output in air:
4.3 - 4.9 mA
Sensor output in distilled water:
17.6 - 18.2 mA
