Dual Tube Technology

Our Dual Tube Sampling System is an efficient method of collecting soil cores with the added benefit of a cased borehole. Dual tube sampling uses two sets of probe rods to collect continuous soil cores or discrete samples. One set of rods is driven into the ground as an outer casing. These rods receive the driving force from the hammer and provide a sealed borehole to prevent the threat of cross contamination. The second, smaller set of rods is placed inside the outer casing. These smaller rods hold a sample liner in place as the outer casing is driven one sampling interval. The small rods are then retracted to retrieve the soil sample from a filled liner.

The main advantage of sampling through cased holes is there is no slough to contend with. In addition, the outer casing effectively seals off the probe hole when sampling through perched water tables or other zones of potential cross-contamination.

The benefits of Dual Tube sampling include:

  • Continuous coring for faster sampling in intervals over 20-feet
  • Continuous coring in both saturated and unsaturated zones
  • Cased borehole eliminates cross contamination
  • Setting monitoring wells through outer casing after collection of soil cores
  • Discrete interval sampling