Field Inspection Pocket Vane Tester is used to measure the undrained shear strength (CU) of cohesive soils, consists of a cylindrical body with a torsional spring and three interchangeable vanes of different sizes used depending upon the expected strength of the soil.
The height/diameter ratio of all vanes is 2.
During operation the vane is driven for 5-6 cm into the soil and then turned with the handle. Deep measures (i.e. on the top of undisturbed samples) can be obtained using the extension rod.