ASTM_D_2878_-_10.pdf

Designation:D287810Standard Test Method forEstimating Apparent Vapor Pressures and MolecularWeights of Lubricating Oils1This standard is issued under the fixed designation D2878;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 a calculation procedure forconverting data obtained by Test Method D972 to apparentvapor pressures and molecular weights.It has been demon-strated to be applicable to petroleum-based and synthetic esterlubricating oils,2at temperatures of 395 to 535K(250 to500F).However,its applicability to lubricating greases hasnot been established.NOTE1Most lubricants boil over a fairly wide temperature range,afact recognized in discussion of their vapor pressures.For example,theapparent vapor pressure over the range 0 to 0.1%evaporated may be asmuch as 100 times that over the range 4.9 to 5.0%evaporated.1.2 The values stated in SI units are to be regarded as thestandard.In cases in which materials,products,or equipmentare available in inch-pound units only,SI units are omitted.1.3 WARNINGMercury has been designated by manyregulatory agencies as a hazardous material that can causecentral nervous system,kidney and liver damage.Mercury,orits vapor,may be hazardous to health and corrosive tomaterials.Caution should be taken when handling mercury andmercury containing products.See the applicable product Ma-terial Safety Data Sheet(MSDS)for details and EPAswebsitehttp:/www.epa.gov/mercury/faq.htmfor addi-tional information.Users should be aware that selling mercuryor mercury containing products into your state or country maybe prohibited by law.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 and health practices and determine the applica-bility or regulatory limitations prior to use.For specificwarning statements,see 6.2,7.1,8.2,and Annex A2.2.Referenced Documents2.1 ASTM Standards:3A240/A240M Specification for Chromium and Chromium-Nickel Stainless Steel Plate,Sheet,and Strip for PressureVessels and for General ApplicationsD92 Test Method for Flash and Fire Points by ClevelandOpen Cup TesterD972 Test Method for Evaporation Loss of LubricatingGreases and OilsD2503 Test Method for Relative Molecular Mass(MolecularWeight)of Hydrocarbons by Thermoelectric Measure-ment of Vapor PressureD2595 Test Method for Evaporation Loss of LubricatingGreases Over Wide-Temperature RangeD2883 Test Method for Reaction Threshold Temperature ofLiquid and Solid MaterialsE659 Test Method for Autoignition Temperature of LiquidChemicals3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 apparent vapor pressure(p),nthe time-averagedvalue of the vapor pressure from the start to the end of theevaporation test.3.1.1.1 DiscussionWhile this may include some effects ofdifferences in nonideality of the vapor,heat of vaporization,surface tension,and viscosity between the m-terphenyl and thelubricating oil,these factors have been demonstrated to benegligible.Unless stated,this average shall cover the range 0 to5 6 1%.3.1.2 cell constant(k),nthe ratio of the amount ofm-terphenyl or lubricating oil carried off per unit volume of gasto that predicted by Daltons law.k 5 22.41 PW/VpM(1)where:k=call constant1This test method is under the jurisdiction of Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.L0.07 on Engineering Sciences of High Performance Fluids and Solids(Formally D02.1100).Current edition approved Oct.1,2010.Published October 2010.Originallyapproved in 1970.Last previous edition approved in 2009 as D287895(2009).DOI:10.1520/D2878-10.2Coburn,J.F.,“Lubricant Vapor Pressure Derived from Evaporation Loss,”Transactions,American Society of Lubricating Engineers,ASLTA,Vol 12,1969,pp.129134.3For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 P=ambient atmospheric pressure,torrW=mass of lubricant evaporated,gV=volume of gas passed through all litres at 273K and101.3 kPa(760 torr)p=apparent vapor pressure,torrM=mole average molecular weight of lubricant vapor,g/moleT=test temperature,KIt has been empirically determined that for m-terphenyl in airk 5 0.12662 12.60/T 2 273!(2)and that the cell constant is independent of the composi-tion of the lubricant.3.1.3 Test Method D972 is normally run with air,whichmay cause changes in easily oxidized fluids.In such cas