The Permeability apparatus is used for the laboratory determination of permeability of soils using a constant of a variable hydraulic head. This test is recommended for soils with the coefficient of permeability in the range of 10³ - to 10 cm/sec. The maximum particle size of the soil which can be tested in the mould is 10 mm.
The equipment comprises the following :
1. Metallic mould, 100 mm dia x 127.3 high x 1000 ml volume.
2. Extension collar, 100 mm dia x 60 mm high
3. Drainage base plate with a recess for a porous stone and with an outlet valve.
4. Metallic clamping ring.
5. Drainage cap (Top plate with a recess for a porous stone and fitted with an inlet valve and an air release valve).
6. Dummy plate to serve as a false bottom during compaction.
7. Porous stone for drainage cap.
8. Porous stone for drainage cap.
9. Set of three glass stand pipes approximately 6 mm dia, 10 mm dia and 20 mm dia mounted on a wooden board.
10. Length of three meter long rubber connecting tube with a pinch cock.
11. Overhead tank made of steel, approximately 37.5 cm dia x 1 meter high. It is provided with an inlet port at the top and six outlet at bottom with cocks and air inlet and water filling tube on top. An arrangement is provided to indicate the water level.