1、Designation:D518816Standard Test Method forVapor-Liquid Ratio Temperature Determination of Fuels(Evacuated Chamber and Piston Based Method)1This standard is issued under the fixed designation D5188;the number immediately following the designation indicates the year oforiginal adoption or,in the case
2、 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.Scope*1.1 This test method covers the determination of the tem-perature at which the vapor formed from a se
3、lected volume ofvolatile petroleum product saturated with air at 0 C to 1 C(32 F to 34 F)produces a pressure of 101.3 kPa(one atmo-sphere)against vacuum.This test method is applicable tosamples for which the determined temperature is between36 C and 80 C(97 F and 176 F)and the vapor-liquid ratiois b
4、etween 8 to 1 and 75 to 1.NOTE1When the vapor-liquid ratio is 20:1,the result is intended tobe comparable to the results determined by Test Method D2533.NOTE2This test method may also be applicable at pressures otherthan one atmosphere,but the stated precision may not apply.1.2 This test method is a
5、pplicable to both gasoline andgasoline-oxygenate blends.1.2.1 Some gasoline-oxygenate blends may show a hazewhen cooled to 0 C to 1 C.If a haze is observed in 12.5,itshall be indicated in the reporting of results.The precision andbias statements for hazy samples have not been determined(see Note 12)
6、.1.3 The values stated in SI units are to be regarded asstandard.1.3.1 ExceptionThe values given in parentheses are pro-vided for information only.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 standa
7、rd to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specificwarnings,see Section 7 and subsection 8.1.1.2.Referenced Documents2.1 ASTM Standards:2D2533 Test Method for Vapor-Liquid Ratio of Spark-Ignition Engine Fuels(W
8、ithdrawn 2008)3D2892 Test Method for Distillation of Crude Petroleum(15-Theoretical Plate Column)D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Perf
9、ormanceD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a Material3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 T(V/L=20),nthe equilibrium temperature at whichthe partial pressu
10、re of a sample under test conditions is equalto 101.3 kPa(14.69 psia)and the vapor-liquid ratio is 20.3.1.2 vapor-liquid ratio of a fuel,nthe ratio at a specifiedtemperature and pressure of the volume of vapor in equilibriumwith liquid to the volume of sample charged,as a liquid,at0 C(32 F).4.Summar
11、y of Test Method4.1 A known volume of chilled,air-saturated sample isintroduced into an evacuated,thermostatically controlled testchamber of known volume or a test chamber with moveablepiston that expands the volume after sample introduction,theinternal volume of which is V/L+1 times of that of the
12、total testspecimen introduced into the chamber.The sample volume iscalculated to give the desired vapor-liquid ratio for the cham-ber volume in use.After injection,the chamber temperature isadjusted until a stable chamber pressure of 101.3 kPa(14.69psia)is achieved.1This test method is under the jur
13、isdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.08 on Volatility.Current edition approved April 1,2016.Published April 2016.Originallyapproved in 1991.Last previous edition approved in 2014 as D5188 14.DOI:10.1520/D
14、5188-16.2For 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.3The last approved version of this historical standard is
15、referenced onwww.astm.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 States1 5.Significance and Use5.1 The tendency of a fuel to vaporize in automotive enginefuel systems is in
16、dicated by the vapor-liquid ratio of the fuel.5.2 Automotive fuel specifications generally include T(V/L=20)limits to ensure products of suitable volatility perfor-mance.For high ambient temperatures,a fuel with a high valueof T(V/L=20),indicating a fuel with a low tendency to vaporize,isgenerallyspecified;converselyforlowambienttemperatures,a fuel with a low value of T(V/L=20)is specified.6.Apparatus6.1 Apparatus suitable for use shall employ a small volumetest chamber incorporating a transduce
