{TAIL ~ Permeability} of a porous, sheet like sample is determined using a device that is designed to measure the pressure differential between a first stream of {HEAD ~ fluid} applied across an entire thickness of a test sample and a second stream of fluid applied across an entire thickness of a reference sample 
{ TAIL ~ Permeability } of a porous , sheet like sample is determined using a device that is designed to measure the pressure differential between a first stream of { HEAD ~ fluid } applied across an entire thickness of a test sample and a second stream of fluid applied across an entire thickness of a reference sample
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH