Designation: D1601 − 18 (Reapproved 2026)Standard Test Method forDilute Solution Viscosity of Ethylene Polymers 1This standard is issued under the f i xed designation D1601; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (´) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the dilutesolution viscosity of ethylene polymers at 135°C. It is appli-cable to a reasonably wide spectrum of ethylene polymershaving densities from 0.910 to 0.970 g/cm 2 . Directions aregiven for the determination of relative viscosity (viscosityratio), inherent viscosity (logarithmic viscosity number), andintrinsic viscosity (limiting viscosity number).1.2 The values as stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3.1 Warning—Mercury has been designated by manyregulatory agencies as a hazardous material that can causeserious medical issues. Mercury, or its vapor, has beendemonstrated to be hazardous to health and corrosive tomaterials. Caution should be taken when handling mercuryand mercury containing products. See the applicable productSafety Data Sheet (SDS) for additional information. Usersshould be aware that selling mercury and/or mercury contain-ing products into your state or country may be prohibited bylaw.N OTE 1—This standard is equivalent to ISO 1628-3.N OTE 2—Appendix X1 – Appendix X3 contain material from theprevious version of Test Method D1601 and are included for informationonly.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards: 2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D446 Specif i cations and Operating Instructions for GlassCapillary Kinematic ViscometersD883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-tics (Withdrawn 2024) 3D4020 Specif i cation for Ultra-High-Molecular-Weight Poly-ethylene Molding and Extrusion MaterialsE2251 Specif i cation for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision LiquidsE2935 Practice for Evaluating Equivalence of Two TestingProcessesIEEE/ASTM SI-10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System2.2 ISO Standards: 4ISO 1628-3 Plastics—Determination of Viscosity Numberand Limiting Viscosity Number—Part 3: Polyethylenesand Polypropylenes3. Terminology3.1 Units, symbols, and abbreviations used in this testmethod are those recommended in IEEE/ASTM SI-10 andTerminologies D883 and D1600.4. Signif i cance and Use4.1 The knowledge of dilute solution viscosity serves as anadditional tool in characterizing ethylene polymers. Viscositydata alone is potentially a limited value in predicting theprocessing behavior of the polymer. However, when used inconjunction with other f l ow and physical property values, thesolution viscosity of ethylene polymers contributes to charac-terizing the material.1 This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved July 1, 2026. Published July 2026. Originally approvedin 1958. Last previous edition approved in 2018 as D1601 - 18. DOI: 10.1520/D1601-18R26.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at www.astm.org/contact. For Annual Book ofASTM Standards volume information, refer to the standard’s Document Summarypage on the ASTM website.3 The last approved version of this historical standard is referenced onwww.astm.org.4 Available from American National Standards Institute (ANSI), 1180 Avenue ofthe Americas, 10th Floor, New York, NY 10036, http://www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1
