5.1 This test method may be used to:

5.1.1 Determine the pore size distribution of a geotextile,

5.1.2 Determine the maximum pore size of a geotextile,

5.1.3 Determine the mean flow pore size of a geotextile,

5.1.4 Determine the effect of processes such as calendaring or needle punching upon the pore size distribution,

5.1.5 Determine the effect of compression upon the pore size distribution of a geotextile, if the test equipment allows, and

5.1.6 Determine the gas flow rate of a geotextile, and thereby its gas flow capability.

5.2 The pore size distribution test may also be used for research, material development, or to assess clogging on field-retrieved samples.

1.1 This test method covers the determination of the pore size distribution of geotextile filters with pore sizes ranging from 1 to 1000 μm.

Note 1: The accuracy of this procedure has been verified up to a maximum pore size of 500 μm. Above this value, accuracy has been found to be equipment dependent and should be verified by the user through checks on materials with known opening sizes.

1.2 The test method measures the entire pore size distribution in terms of a surface analysis of specified pore sizes in a geotextile, defined in terms of the limiting diameters.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.