• DFI India
  • DFI Trust

N Value, SPT Value

The number of blows required to drive a 2 in. O.D., 1 3/8 in. I.D., 24 in long, split soil sampling spoon one foot with a 140 lb. Weight freely falling 30 in. The count is recorded for each of three six-inch increments. The sum of the second and third i