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ECH2O Soil Moisture Sensor


A low cost sensor for measuring volumetric soil water content

Measuring or monitoring soil moisture content helps determine when to irrigate, how much water to apply, depth of wetting, patterns of soil moisture extraction by roots, and trends in soil moisture content with time. Soil moisture determines the transport and storage of dissolved nutrients and pollutants and the availablity of water to plants.

Principle of measurement

Designed by Decagon, a leading US instrumentation manufacturer, ECH2O is a capacitance probe that measures dielectric permittivity of the surrounding medium. In soil, dielectric permittivity is directly related to the water content. The ECH2O probe outputs a voltage proportional to the dielectric permittivity, and therefore the water content of the soil.

ECH2O sensors and logger systems

Click here for a comparison of all the different ECH2O soil moisture sensors.