ASTM D 646 : 2025

1.1This test method covers the determination of the mass per unit area and density of aramid paper and paperboard.

1.2Mass per unit area is expressed in grams per square meter (g/m²) or ounces per square yard (oz/yd²). Density is expressed in grams per cubic centimeter (g/cm³ ) or (ounces per cubic yard (oz/yd³).

1.3The 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.

1.4This 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.

1.5This 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.