1、Designation:D674802a(Reapproved 2012)Standard Test Method forDetermination of Potential Instability of Middle DistillateFuels Caused by the Presence of Phenalenes andPhenalenones(Rapid Method by PortableSpectrophotometer)1,2This standard is issued under the fixed designation D6748;the number immedia
2、tely 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 meth
3、od covers a procedure3for the rapiddetermination of phenalenes and phenalenones in middledistillate fuels,including marine,automotive,heating,and gasturbine fuel such as those specified in Specifications D396,D975,D2069,and D2880.Phenalenes and phenalenones affectthe potential instability of fuels,l
4、eading to fuel degradationproducts during storage,which may cause performance prob-lems.1.2 This test method is applicable to both dyed and undyedfuels at all points in the distribution chain from refinery toend-user.It is not applicable to fuels containing residual oil.The portable apparatus allows
5、 the whole test to be conductedon site or in a laboratory and does not require the test sampleto be heated.1.3 This test method is suitable for testing samples with arelative absorbance of up to 5.00 absorbance units(AU).NOTE1The precision of the test method has been established onrelative absorbanc
6、e up to 1.00AU.For relative absorbance above 1.00AUthe precision may not apply.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 determi
7、ne the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:4D396 Specification for Fuel OilsD975 Specification for Diesel Fuel OilsD2069 Specification for Marine Fuels(Withdrawn 2003)5D2880 Specification for Gas Turbine Fuel OilsD4057 Practice for Manual Sa
8、mpling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4306 Practice for Aviation Fuel Sample Containers forTests Affected by Trace ContaminationD4625 Test Method for Middle Distillate Fuel StorageStability at 43 C(110 F)D5854 Practice for M
9、ixing and Handling of Liquid Samplesof Petroleum and Petroleum ProductsD6468 Test Method for High Temperature Stability ofMiddle Distillate FuelsE131 Terminology Relating to Molecular SpectroscopyE275 Practice for Describing and Measuring Performance ofUltraviolet and Visible Spectrophotometers2.2 O
10、ther Standards:6Def Stan 05-50 Methods for Testing Fuels and Lubricantsand Associated Products,Part 40 Storage Stability ofDiesel FuelsDef Stan 914 Fuel,Naval,Distillate NATO Code:F76 JointService,Designation DIESO F763.Terminology3.1 Definitions:1This test method is under the jurisdiction of ASTM C
11、ommittee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 2002.Last previous edition approved in 2007 as D674802a(
12、2007).DOI:10.1520/D6748-02AR12.2This test method is being jointly developed with the Institute of Petroleumwhere it is designated IP 463.3This process is covered by US Patent 5,378,632.Interested parties are invitedto submit information regarding the identification of an alternative(s)to thispatente
13、d item to ASTM International Headquarters.Your comments will receivecareful consideration at a meeting of the responsible technical committee,whichyou may attend.4For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of A
14、STMStandards volume information,refer to the standards Document Summary page onthe ASTM website.5The last approved version of this historical standard is referenced onwww.astm.org.6Available from United Kingdom Defence Standardization,Room 1138,Kenti-gern House,65 Brown Street,Glasgow,G2 8EX.United
15、Kingdom.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.1 For definitions of terms relating to absorption spec-troscopy see Terminology E131.Terms of particular signifi-cance are the following:3.1.2 radiant energy,nenergy transmitted
16、as electromag-netic waves.3.1.3 radiant power P,nthe rate at which energy istransported in a beam of radiant energy.3.2 Definitions of Terms Specific to This Standard:3.2.1 absorbance,A,nthe logarithm to the base 10 of thereciprocal of the transmittance,T.In symbols:A 5 log101/T!5 2log10T(1)where:T=transmittance as defined in 3.2.5.3.2.2 absorbance units(AU),nunits of relative absor-bance reported by the portable spectrophotometer.3.2.3 pathlength of test portion b,nthe distance in mm,measured i
