Small drill-hole, gas mini-permeameter probe

This invention is most generally characterized as a research instrument. It is a device used in research in geology. More specifically, it is a device used in the field to measure physical properties of rocks and similar geological materials. Even more specifically it is a device used to measure the permeability of rocks and similar geological materials in their natural (field) setting. The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.