Method for control gas diffusion and bubbles formation in liquid   porosimetry
  The main problem in liquid porosimetry, which prevents to see the pore sizes smaller than 2 microns in diameter, is direct gas diffusion flow through a micro-porous membrane. This diffusion causes bubbles formation below the membrane and that spoils extrusion (intrusion) data, as one cannot distinguish the volume of extrusion (intrusion) liquid from the volume of formatted bubbles. The suggested below method cures the problem by creating the liquid flow below the membrane. The flow washes out all of the small bubbles preventing them to grow. That allows using the membrane at higher differential pressures, even higher than minimum bubble point of the membrane, without spoiling data. 
V.Smiricinschi