HUMBOLDT H-4220F Single Mass Dynamic Penetrometer

Humboldt H-4220F (5DPL1) foundation, single-mass dynamic cone penetrometer (DCP) is ideal for estimating the shear strength of weak soil having a CBR (California bearing ratio) less than 20 and psf (pounds per square feet) less than 4000. This single-mass dynamic penetrometer can also measure the localised strength, CBR & thickness of the undisturbed soil and other compacted materials. It is suitable for horizontal construction applications like shallow footings, foundations & pavement shoulders.

Working Mechanism:

• Hold the single-mass dynamic penetrometer in the vertical position against the soil surface.
• Lift the sliding hammer till it touches the handle and release it to allow the hammer to strike the anvil coupler assembly.
• Count the blows required for driving 2-inch increments on the drive rod into the soil.
• Compare the number of blows to the chart on the instruction manual for determining an estimate of CBR or PSF.

Features:

• Humboldt H-4220F (5DPL1) single-mass dynamic penetrometer is ideal for assessing properties of material.
• It comes with a drive rod (marked in 2 inch increments), quick connect pins, wrenches, a reusable hardened point and a single mass hammer
• The drive rod and hammer are connected with a quick-connect pin.
• The hammer drop is 22.6 inches and the hardened point has a 60-degree angle.

Compatible Accessories:

• Humboldt H-4219QC.12 Dual-Mass DCP Drive Rod: These drive rods are used to replace the old, worn-out or damaged drive rods in this penetrometer.
• Humboldt H-4219.8 Dual-Mass DCP Extension Rod: These extension rods increase the depth up to which this penetrometer can test the soil.

Standards and Approvals:

• ISO 9001:2015
• ASTM D6951

Frequently Asked Questions:

Q. What type of soils are measured by single mass dynamic penetrometers?

A. Single Mass DCPs estimate the shear strength of fine / grained soils, weak stabilized / modified materials and granular construction materials. They should not be used in materials containing aggregates greater than 2 inches (50 mm).

Q. What to do if soil aggregates are greater than 2 inches?

A. Aggregates having sizes greater than 2 inches stop penetration or cause a deflection of the drive rod. If the unit has not penetrated more than 0.08 inches (2 mm) even after 3 blows or the handle has got deflected from the vertical position by more than 3 inches (75 mm), users should move to a new test location with a distance greater than 12 inches (300 mm) from the prior location. It prevents any damage to the units and minimises any test error.