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TAPPI
T 460 om-21
Air resistance of paper (Gurley method)
2021
7
offline
This method is used to measure the air resistance of approximately 6.45 sq. cm. (l sq. in.) circular
area of paper using a pressure differential of 1.22 kPa. The recommended range of the liquid column instrument is
from 5 to 1800 seconds per 100 mL cylinder displacement. For more impermeable papers the time requirements
become so excessive that other techniques are preferable. ....