ASTM D 2238:2022

1.1 These test methods cover measurement by infrared absorption spectrophotometry of the 1378 cm⁻¹ (7.25 μm) band in polyethylene due to methyl groups. ( 1 , 2 , 3- 6 ) 2 Two test methods are covered: 1.1.1 Test Method A uses compensation with a standard sample film of known methyl content. 1.1.2 Test Method B uses compensation with a wedge of polymethylene or a polyethylene of known low methyl content. 1.2 These test methods are applicable to polyethylenes of Types I (density 0.910 to 0.925 g/cm³), II (density 0.926 to 0.940 g/cm³), and III (density 0.941 to 0.965 g/cm³). Note 1: For determination of density, see Specifications D1505 . Note 2: In cases of Type III polyethylene with densities greater than 0.950 g/cm³, different results are obtained with the two test methods. 1.3 The values stated in SI units are to be regarded as the 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. Specific hazards statements are given in Section 7 . Note 3: There is no known ISO equivalent to this standard. 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.

83.080.20