Sampling of granular material for analysis

摘要

A method of and apparatus for sampling granular material where a substantially vertical sampling tube is subjected to axial, and/or rotational oscillations to reduce the vertical vector component of the friction force between the granular material and the tube to be substantially equal to the weight of an elemental disc of the material in the sampling tube. The acceleration force on the disc is substantially zero and the material has no pressure gradient or bulk density gradient.