There are different types of push ahead samplers on the market, and each one is a little different. However, what they have in common is the ability to advance a soil sample barrel to the desired interval below grade. The barrel provides structure to keep the borehole from collapsing while the sample is collected below.
Push ahead samplers are named based on how they work: the tool is driven ahead of the drilling operation, where drilling disturbance has not occurred yet. After being driven a distance of 18 to 24 inches, the device is pulled back and/or twisted (there are a variety of ways to open) a short distance to expose a screen. From there, a bailer can be run in the string to collect a sample.
A push ahead sampler often saves times compared to other methods because you don’t have to sample continuously to the terminal depth.
Another reason many people use the push ahead method is that it minimizes the potential for cross contamination when collecting discrete samples.
Using push ahead sampling gives you the ability to quickly and efficiently recover soil samples at identified intervals, minimize the potential for cross contamination, and eliminates soil cuttings that would need to be dealt with at an additional cost.