• Geo Gauge (Humboldt Stiffness Gauge)
• Moisture Density Gauges
• Marshall Compression Testing Machines

• Sieves- U.S.A. Standard
• Sieve Shakers
• Triaxial/Hydraulic Conductivity Testing Equipment
  Ovens:

• Moisture Determination Ovens
• Heavy Duty Ovens
• Vacuum Ovens

The Humboldt Stiffness Gauge (HSG)

The Humboldt Stiffness Gauge is a field instrument that nondestructively measures soil stiffness and soil modulus. The HSG vibrates, imparting small forces to the soil through a ring-shaped foot, and causes small soil deflections.

The instrument determines soil stiffness as the ratio of these small forces to small deflections.
It assumes a value of Poisson's ratio and derives Young's soil modulus from the stiffness. HSG measures soil stiffness in just over a minute. Soil stress and strain are determined by HSG at levels commonly found in soil applications (3 to 5 psi).
Because it vibrates from 100 Hz to 200 Hz, HSG filters out soil deflections caused by nearby equipment. By using soil stiffness measured with HSG along with statistical quality control, the current over specification and overcompaction of soil can be greatly reduced, thereby reducing compactive effort by approximately 30%. 
     When soil is compacted for pavements, pipe bedding, backfills, and foundations, soil density is used almost exclusively by the construction industry to specify, estimate, measure and control soil compaction. However, soil density may not be the desired engineering property, instead, the desired engineering property is the soil modulus or soil stiffness. 

A state of the art compaction control gauge featuring a totally enclosed and sealed automatic indexing mechanism. The HS-5001 B provides an accurate read-out of the measurement depth while keeping abrasive dirt or other debris out of the mechanism itself. Six convenient, easily replaced size AA alkaline batteries last up to 2000 hours operation.

Other features include:

• Built- in fist routines
• Nomograph method for thin lift asphalt measurements
• Five block calibration method - No short cuts
• Indexing mechanism is specially designed for positive, precise and repeatable source positioning
• Durable bronze bearings reduce source rod lateral movement
• Rugged, precision-machined base from solid 6061 -T6 aluminum, unlike castings will never warp from costing stress
• Meets and exceeds ASTIR test methods D2922, D3017, D2950, C 1040 and AASHTO T238, T239

All Humboldt Marshall testing equipment meets specifications for these ASTM, AASHTO and British Standard tests: ASTM D1559, AASHTO T245, BS 598: Part 107

Humboldt's new Marshall compression and testing machine with electro-mechanical load frame has 1¼" diameter continuously threaded steel strain rods and heavy-duty cross head. That design gives nearly twice the rigidity of other frames on the market. This superior construction provides less deflection in the load frame -- so your test results are more reliable.

ADVANTAGES

• Improve stability in testing
• Inexpensive, easily replaced batteries
• Improve stability and flow monitoring and measuring
• Increase reliability of test results
• Reduce your equipment repairs
• Increase your productivity