Dual tube sampling system

摘要

The invention pertains to the art of direct push soil sampling that uses the art of dual tube to retrieve subsurface soil samples. It is a means of applying the dual tube art that allows deeper sampling depths to be achieved by configuring the tooling string in such a manner that the inner tooling is non-rigidly attached to the outer tooling string both rotationally and axially. The non-rigidity of integration of the two tooling strings allows deeper penetration of the sampling apparatus by reducing the friction between soil entering the sample chamber of the inner tooling string and the sample chamber. In addition deeper depths of penetration are possible because the inner and outer tooling strings are driven both concurrently and independently of each other.