The Stationary Piston Type Sampler is a thin wall tube sampler equipped with a piston assembly. The piston is held at the forward end of the tube until the depth is reached at which a sample is to be secured. Then the piston rod, which extends to the surface, is clamped firmly in place and the tube pressed or jacked under steady pressure past the piston into the soil to be sampled.

The piston creates a vacuum which assists in the sampling of “hard to hold” materials such as fine silts and some clays.

After the sampler has been removed from the hole, it is necessary to relieve the vacuum over the sample before removing the piston. This is done by giving the piston rod several backward turns, thus admitting air to the top of the tube. Then the tube is detached, sealed, capped, and sent to the laboratory. The recovered samples are suited for any of the various laboratory tests. Steel tubes are furnished unless otherwise specified.