5.1 Thickness is one of the basic physical properties used to control the quality of many geosynthetics. Thickness values can be required for calculation of some geosynthetics properties such as permeability and tensile stress, among others.

5.2 The thickness of some geosynthetics may vary considerably with the applied normal load. Specific pressures and surfaces on which they are applied are indicated in this method to ensure all results are comparable.

5.3 These test methods may be used for acceptance testing of commercial shipments of geosynthetics for which this method is applicable (see 1.1).

1.1 These test methods cover the measurement of the nominal thickness of geosynthetics, except textured and some structured geomembranes where the entire surface of the presser foot cannot come into complete contact with the geosynthetic surface. Use Test Method D5994/D5994M for textured geomembranes and Test Method D6525/D6525M for rolled erosion control products.

1.2 These test methods do not provide thickness values for geosynthetics under variable normal compressive stresses. These test methods determine nominal thickness, not necessarily minimum thickness.

1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

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.