The Falling Head Permeameter is one of the basic equipments used in evaluating the permeability of fine-grained soils inclusive of clay and silt. This testing tool is used to conduct the falling head permeability test; a predominant technique in the determination of permeability of soil. The application of Falling Head Permeameter test is more effective in intermediate to low permeable soils whereby it is effective for fine grained soils.

The Falling Head Permeameter designed with the clear acrylic chamber will able to observe the test specimen during the test. It comes fitted with three manometer tubes with the inner diameter of approximately 4mm, 5 mm and 11mm to cater for varying levels of permeability of the soil. To make the permeameter even more user-friendly the unit is also supplied with a soaking reservoir, tubing, and connectors.

In order to perform a test, the soil sample must be saturated with de-aired water and this has been made possible with the de-airing tank which is provided and has been made of high quality acrylic plexiglass. The portable vacuum pump titled 230V, 1ph, 50Hz and nylon tube of 20 meters allow the efficient saturation of the sample.

In Falling head permeameter test the water is given permeation through the sample and the rate of decline of the water level in the stand pipe is closely monitored. In this test, the nature of permeability of the soil is established from the time taken by the water levels to fall from the upper level to the lower one. Besides, the Falling Head Permeameter has a water trap to collect the condensed water which affects the results of the test.

This equipment can be employed in constant and falling head methods of permeability test. Ann is available in various sizes and they vary depending on the size of the frame as follows; 5 to 9 inches (6. 3–22. 8 mm) in diameter to contain various sizes of soil particle sizes. The Falling Head Permeameter is also essential for geotechnical laboratories as an effective tool for conducting accurate permeability tests on granular soils.