Premium
POROSITY: VI. DETERMINATION OF POROSITY BY THE METHOD OF GAS EXPANSION *
Author(s) -
Washburn Edward W.,
Bunting Elmer N.
Publication year - 1922
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1922.tb17640.x
Subject(s) - porosimetry , porosity , volume (thermodynamics) , materials science , work (physics) , composite material , ceramic , mineralogy , porous medium , thermodynamics , chemistry , physics
Theory of the method. —The pore volume is measured by allowing the gas which fills the pores to expand into a measured volume and measuring the accompanying fall in pressure. Applicability. —The method is in general applicable to pieces of any size and shape and to all classes of porous bodies or materials. A new porosimeter. —For rapid work with shaped test pieces a new porosimeter is described. The new instrument measures accurately both pore volume and bulk volume. A complete porosity determination can be made in 5 minutes. No weighing is required. The results on ceramic bodies arc reproducible to one unit in the first decimal place of the per cent porosity. Considerably higher accuracy than this can be secured if desired. Results. —The results obtained with the new method are in all cases higher, in a number of cases very much higher, than those obtained by the methods of liquid absorption in current use. For fired bodies the same results are obtained with dry air, hydrogen or helium as the pore filling gas. The results show conclusively that complete filling of all the pores in a reasonable time can not be secured by any of the current methods using a liquid as the pore filling agent.