Hood Infiltrometer

Hood Infiltrometer

The hood infiltrometer developed by UGT is used to measure the hydraulic conductivity of soils in near saturated areas in field tests (SCHWÄRZEL & PUNZEL 2007). The device consists of three components: 1) hood, 2) Mariotte water supply consisting of an infiltration vessel, bubble tower and ventilation tube and 3) U-tube pressure gauge. The infiltration takes place from a closed hood placed on the ground (open at the bottom) and filled with water. The water-covered, circular soil surface under the hood forms the source area for the infiltration flow. No additional contact layer or preparation of the soil surface is required on the measuring surface. This not only saves working time, but also makes it possible to determine the infiltration or hydraulic conductivity non-destructively under completely natural conditions. The pressure under the hood is controlled via a Mariotte water supply. The effective hydraulic pressure head on the ground surface can be freely selected between zero and a negative pressure up to the air passage point of the ground. The hydraulic pressure head is precisely displayed via a U-tube pressure gauge. The hydraulic conductivity is calculated from the steady flow rates determined in the test run according to WOODING (1968).