Proctor Penetrometer Set
Establishes the moisture-penetration resistance relations of fine-grained soils. Includes these interchangeable needles ( area in sq. in. or sq. cm) : 1 ( 6.45) , 3/ 4 ( 4.84) , 1/ 2 ( 3.22) , 1/ 3 ( 2.15) , 1/ 5 ( 1.29) , 1/ 10 ( .65) , 1/ 20 ( 0.32) 1/ 30 ( 0.22cm2) and 1/ 40 ( 0.16cm2) . Replacem