ASTM_D_8206_-_18.pdf

Designation:D820618Standard Test Method forOxidation Stability of Lubricating GreasesRapid Small-Scale Oxidation Test(RSSOT)1This standard is issued under the fixed designation D8206;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 quantitative determinationof the oxidation stability of lubricating greases with a droppingpoint above the test temperature.1.2 This test method determines the resistance of lubricatinggreases to oxidation when stored statically in an oxygenatmosphere in a sealed system at an elevated temperature underconditions of test.1.3 The values stated in SI units are to be regarded as thestandard.No other units of measurement are included in thisstandard.1.4 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.1.5 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:2D942 Test Method for Oxidation Stability of LubricatingGreases by the Oxygen Pressure Vessel MethodD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricants2.2 ISO Standard:3EN 60751:2008 Industrial platinum resistance thermometersand platinum temperature3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 break point,npressure in the test instrument,whichis 10%below the maximum pressure of the actual test run.3.1.2 induction period,ntime elapsed between starting theheating procedure of the pressure vessel and the break point,measured in minutes.4.Summary of Test Method4.1 For this test,4.00 g 6 0.01 g of sample is weighed in aglass dish at a temperature of 20 C 6 5 C and thenintroduced into a pressure vessel,which is subsequentlycharged with oxygen to 700 kPa 6 5 kPa.4.1.1 The test is initiated by heating the pressure vessel to atemperature of 140 C 6 0.5 C or 160 C 6 0.5 C,dependingon the selected test.4.2 The pressure is recorded continuously until the breakpoint is reached.5.Significance and Use5.1 This test method measures the net change in pressureresulting from consumption of oxygen by oxidation and gain inpressure due to formation of volatile oxidation by-products.This test method may be used for quality control to indicatebatch-to-batch uniformity.It predicts neither the stability ofgreases stored in containers for long periods,nor the stabilityof films of greases on bearings and motor parts.5.2 Induction period as determined under the conditions ofthis test method can be used as an indication of oxidationstability.This test method can be used for research anddevelopment,quality control,and specification purposes.However,no correlation has been determined between theresults of this test method and service performance.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.09.0E on Oxidation of Greases.Current edition approved June 1,2018.Published July 2018.DOI:10.1520/D8206-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright 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 6.Apparatus6.1 GeneralThis test method uses an automatically con-trolled oxidation tester4(see Fig.1),comprising a pressurevessel capable of being heated quickly and fitted with apressure sensor capable of measuring pressures up to 1800 kPaand a temperature sensor capable of reading to 0.1 C accuracy.Pressure and temperature in the pressure vessel are recordedcontinuously during the test.The pressure vessel is fitted