The most widely accepted, portable method for evaluating strength and density of soil, in situ. The dynamic cone penetrometer uses a 15 lb. (6.8 kg) drive mass falling 20 in. (50.8 cm) that strikes the anvil to cause penetration of 1.5 in (3.8 cm) diameter cone (45 degree vertex angle) that has been seated in the bottom of a pre-augered hole. The blows required to drive the embedded cone a depth of 1 3/4' have been correlated by others to N values derived from the Standard Penetration Test (SPT). Experience has shown effectiveness in pre-augered holes to depths of 15' - 20' (4.6 to 6.1 cm). The cone can be replaced with a plated drive tube assemble for collection of 3' x 10' (7.6 x 25.4 cm) samples in preaugured holes.