1、Designation:D768911Standard Test Method forCloud Point of Petroleum Products(Mini Method)1This standard is issued under the fixed designation D7689;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
2、 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 cloudpoint of petroleum products,biodiesel,and biodiesel blends,that are transparent in layers 40 m
3、m in thickness,using anautomatic instrument.1.2 This test method covers the range of cloud pointtemperatures from-50 to+6C.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of t
4、hesafety 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 of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D2500 Test Method for Cloud Po
5、int of Petroleum ProductsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Sam
6、e Property of a Material2.2 Energy Institute Standard:3IP219 Test Method for Cloud Point of Petroleum Products3.Terminology3.1 Definitions:3.1.1 biodiesel,nfuel comprising mono-alkyl esters oflong-chain fatty acids derived from vegetable oils or animalfats,designated B100.3.1.1.1 DiscussionBiodiesel
7、 is typically produced by areaction of vegetable oil or animal fat with an alcohol such asmethanol or ethanol in the presence of a catalyst to yieldmono-esters and glycerin.The fuel typically may contain up to14 different types of fatty acids that are chemically transformedinto fatty acid methyl est
8、ers(FAME).3.1.2 biodiesel blend(BXX),nblend of biodiesel fuel withpetroleum-based diesel fuel designated BXX,where XX is thevolume percentage(as a whole number without the percentagesign)of biodiesel.3.1.3 cloud point,n in petroleum products and biodieselfuels,the temperature of a liquid specimen wh
9、en the smallestobservable cluster of hydrocarbon crystals first occurs uponcooling under prescribed conditions.3.1.3.1 DiscussionThe cloud point occurs when the tem-perature of the specimen is low enough to cause hydrocarboncrystals to precipitate.In a homogeneous liquid,the cloud isalways noted fir
10、st at the location in the specimen where thespecimen temperature is the lowest.The cloud point is thetemperature at which the crystals first occur,regardless of theirlocation in the specimen,and not after extensive crystallizationhas taken place.The hydrocarbon crystals that precipitate atlower temp
11、eratures are typically,but not excluded to,straightchain hydrocarbons commonly called“wax crystals.”3.2 Definitions of Terms Specific to This Standard:3.2.1 D2500/IP219 equivalent cloud point,ntemperatureof a specimen,in integers,calculated by applying a bias androunding the results of this test met
12、hod to the next lowerinteger(see 12.2).3.2.1.1 DiscussionThis test method produces results with0.1C resolution.Should the user wish to provide results witha similar format to Test Method D2500,then this calculationcan be performed.Some apparatus can perform this calculationautomatically.3.2.2 mini m
13、ethod,n in cloud point test methods,auto-matic test procedure using a small sample size,prescribedcooling rate,specimen receptacle,and optical system fordetection of crystal formation.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants a
14、nd is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Current edition approved July 1,2011.Published August 2011.DOI:10.1520/D768911.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandar
15、ds volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Energy Institute,61 New Cavendish St.,London,WIG 7AR,U.K.,http:/www.energyinst.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.2
16、.1 DiscussionThe prescribed cooling rate is de-scribed in 4.1,the specimen receptacle is described in 7.1,andthe optical system for detection of crystal formation is de-scribed in 4.1.4.Summary of Test Method4.1 After inserting the test specimen into the automaticapparatus,and initiation of the program,the test specimen isheated,if necessary,to a starting temperature and then cooledby prescribed rates(11.5 and 11.6).The test specimen iscontinuously monitored for appearance of hydrocarbon crystal