dual head infiltrometer for saturated soil hydraulic conductivity


infiltrometer dual head saturoThe infiltrometer dual head, the SATURO, manufactured by METER Group (formally Decagon Devices), measures soil saturated hydraulic conductivity (Kfs).

The SATURO is fully automated and requires no post-processing of data. It is easy to install, use and maintain. Therefore, the SATURO provides accurate and reliable scientific data on saturated soil hydraulic conductivity.

The SATURO is comparable, or analogous, to a double-ring infiltrometer. But, there are fundamental differences and research has proven the SATURO is more accurate. For more information, see below.



No babysitting - Set it up and leave it to add water, maintain correct pressure heads, measure infiltration rates, and calculate K. That is, the SATURO is completely automated.

Easy to carry - Sized for one person to easily carry and install. Also, an optional carry case is available.

Simple installation - Just hammer in the ring, connect the hoses, and set the parameters on the device.

Run 3-4 units simultaneously - Designed and priced so you can account for spatial variability.

Eliminate "Guess Factor" - The infiltrometer measures infiltration at two different pressure heads to find (rather than estimating or guessing) the soil macroscopic capillary length factor (alpha). Therefore, the SATURO is an accurate scientific measurement of hydraulic conductivity.

Use less water - The SATURO uses air pressure to maintain the pressure heads. There is no need to adjust and measure water levels.

Proven method - The SATURO is an automation of the method used by Reynods and Elrick (1990), and others, for the quantification of saturated soil hydraulic conductivity.


infiltrometer dual head - how does it work?

Pound a ring into the soil, seal on the Infiltrometer Head, and connect the hoses to the control unit. Set up the test.

The Infiltrometer will pond water on top of the soil and use air pressure to create two different pressure heads. It will automatically maintain the correct water levels and will measure infiltration rates through two complete pressure cycles. The control unit collects all data and performs the calculations to determine field saturated hydraulic conductivity (Kfs).

All data can be downloaded from the control unit for further analysis.


theory of the infiltrometer dual head

Water flows through soil in three dimensions. In the early days of infiltrometers, it was simply impossible to solve two and three dimensional equations, so the dual ring infiltrometer was created to try to physically force water to flow in one dimension.

Now that we can do the math, the single ring infiltrometer is an easier--and better--method. However, if you're using a single head or a changing head, you still need to know--or guess--the "alpha factor" (soil macroscopic capillary length) to solve the equations.

Reynolds and Elrick (1990) showed that by solving the equations at two different pressure heads, alpha drops out, allowing you to determinesaturated hydraulic conductivity without making any assumptions.


SATURO versus double-ring infiltrometer

The SATURO and the double-ring infiltrometer are both ring infiltrometers that infiltrate water from the surface into soils. Overall, they compare fairly well. But, the main difference is how they deal with three-dimensional flow in the field saturated hydraulic conductivity (Kfs) calculation.

The SATURO uses the multiple-ponded head analysis approach to get a more direct estimation of alpha, which is used to determine how the soil pulls the water laterally. The double-ring infiltrometer uses a larger outer ring to act as a buffer from three-dimensional flow. Therefore, the double-ring infiltrometer requires more water and literature suggests that it doesn’t perform well.

Also, with a double-ring infiltrometer, there is still a need to estimate alpha in the equations. This is typically done from a look-up table based on soil type and often results in error. Therefore, overall, the SATURO has many advantages over the traditional double-ring infiltrometer.


SATURO explained


manual & docs

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