Proctor Penetrometer Set

The Proctor Penetrometer Set can be used to establish the moisture-penetration resistance relations of fine-grained soils per ASTM D1558.

The Proctor Penetrometer Kit consists of a special spring dynamometer, with a pressure indicating scale on the stem of the handle, which is graduated from 10—130lbf (45—580N) in increments of 2lbf (9N). A sliding ring on the stem indicates the shear strength obtained with the test. The kit includes these interchangeable needles (area in in.² or cm²): 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 (0.22) and 1/40 (0.16). Replacement needles are available, see accessories below. The kit comes with a foam-lined, wooden box that provides storage for the penetrometer and the interchangeable needles.

Before using the Proctor Penetrometer soil samples should be prepared in accordance with either method “A” or method “B” of ASTM D698. After preparation, the fraction passing the #4 sieve (4.75mm) must have at least 20% passing the 3/8" (9.5mm) sieve to comply with the ASTM D1558 standard.

Note: Penetration resistance determinations are not reliable for very dry molded soil specimens or very granular soils.