5.1 Thickness is one of the basic index properties used to control and track the quality of many geomembranes. Additionally, many mechanical properties (for example, tensile yield strength, puncture strength, etc.) can be related to core thickness. Core thickness values may also be required in calculation of some parameters such as diffusion coefficients or tensile stresses.

5.2 The measured core thickness of geomembranes may vary considerably depending on the pressure applied to the specimen during measurement. To reduce variation in measurements and the chance of unrealistically low values due to excessively high pressures, a specific gauge point geometry and applied force are prescribed in this test method.

5.3 The test method is applicable to all commonly available textured geomembranes that are deployed as manufactured geomembrane sheets.

1.1 This test method covers a procedure to measure the core thickness of textured geomembranes.

1.2 This test method does not provide thickness values for geomembranes under variable normal stresses.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

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.