The tension infiltrometer is an instrument designed to measure the coefficient of saturated hydraulic conductivity in the field (Kfs) within the soil horizon of interest, at different tensions as recommended by the Chilean Standard NCh 3610.Of.2020.

The test consists of measuring the infiltration flow rate into the target soil horizon through the porous membrane incorporated in the tension disc, which receives water from the reservoir tower graduated in millimeters for continuous field measurement. This tower is connected to a Mariotte tube, which maintains a constant preset pressure by transferring air into the reservoir tower as the water infiltrates into the soil.

The use of the tension infiltrometer provides more precise results compared to conventional methods for determining soil hydraulic conductivity.