Porosity

Description

The volume of open space, or interstices, within a solid material. Porosity is expressed as a percentage of the total void volume ratioed to the total volume of a material. A rough test for the porosity of a small stone or ceramic piece is to dry the object, weight it, then soak it in water for 12 hours and re-weigh. The weight difference corresponds to the amount of absorbed water. The porosity of paper is generally measured with commercial testing equipment, such as the Gurley Densometer or the Sheffield porosimeter.

Synonyms and Related Terms

Porigkeit (Deut.); Porosität (Deut.); porosité (Fr.); porosidade (Port.)

Physical and Chemical Properties

% porosity = (Vv x 100)/ Vt where Vv = volume of voids and Vt=vtotal volume

Resources and Citations

• ASTM, Standard Terminology of Microscopy, Annual Book of ASTM Standards, Section 14, General Methods and Instrumentation, ASTM, E175, 75-78, May 1982

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

• José Delgado Rodrigues, LNEC, Submitted information, 2009.

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

• Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982

• Boise Cascade Paper Group, The Paper Handbook, Boise Cascade, Portland OR, 1989