Humboldt H-4210A Portable, Static Cone Penetrometer - Manual (Page 2)

Portable, Static Cone Penetrometer
Information
The H-4210A Static Cone Penetrometer is an unparalleled device for measuring soil
consistency. It is specifically designed for use in fine grained, soft soils to depths as much
as 30 feet. The basic unit is totally self contained, weighs 5 Ib, and is set up for a 2-ft
maximum depth. It is intended to be operated by one person and requires no auxiliary
equipment. The device is extremely rugged and is built for day-in, day-out use.
Practical Applications
• Rapid selection of locations for field density tests
• Evaluating backfills in trenches and behind walls
• Light foundation investigations
• For rapid correlation of field CBR tests
• Earthwork control for embankments
• Muck and soft soil probes
• Probing shallow marine deposits
• Probing beneath existing shallow foundations
• Pavement subgrade evaluation
Operating Instructions
Dual rods enable the cone stress to be measured directly. Soil friction on the outer rod
does not influence the reading. Depending upon the application, either the maximum
bearing for an increment of push or the least bearing for an increment can be reported.
If you were investigating for soft spots, you would take the least reading. In typical use,
you would force the cone into the soil 6 inches, retract the cone slightly until the gauge
reads zero, then advance an additional 6 inch increment. If you meet with refusal, the
cone can be removed and the hole opened with a hand auger to permit a continuation
of measurements against depth.
The tool has been designed to allow a maximum force of 250 Ibf to be applied,
somewhat more than the average weight of an operator. The unit can be operated in a
vertical or horizontal position. The cone tip has an included angle of 60°. The cone has a
section area of 1.5 cm
2 . The maximum total bearing (Q
c
) is 70 kg/cm 2 .
The H-4210A penetrometer assembly comes standard with a 2-ft Inner/Outer “starter”
rod assembly. If you wish to use extensions, it will be necessary to purchase the
H-4210E.2A, 2-ft “extension” Inner/Outer Rod assembly.
Note: Starter Inner Rods are 0.875 inch longer than the similar-looking Extension Inner
Rods (i.e., the overall length for the 2-ft Starter Inner Rods is 24.875 in. and for the
Extension Inner Rods is 24 in; the Starter and Extension Outer Rods have the same
length).
Simple determination of approximate unconfined compression strength, standard
penetration test "N" and CBR values can be derived from the cone index.