GSR Pocket Penetrometer CL24550The GSR Pocket Penetrometer is used for the evaluation of shear strength and approximate determination unconfined compressive strength in the classification of insitu cohesive materials. The stainless steel piston (diameter 6. 4mm) is pressed into the soil until the engraved line, 6. 4mm from the tip, is flush with the surface. A reading is then taken from the engraved scale which is calibrated in kPa. The accuracy of this instrument increases with