1、Designation:D746420Standard Practice forManual Sampling of Liquid Fuels,Associated Materials andFuel System Components for Microbiological Testing1This standard is issued under the fixed designation D7464;the number immediately following the designation indicates the year oforiginal adoption or,in t
2、he 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.INTRODUCTIONThere are several important characteristics that distinguish microbiological parameters fr
3、om otherparameters for which manually collected fuel samples are tested.Microbes,when present in fuels or fuel systems are invariably present as contaminants.Similarlyto particulates,microbes are discrete entities rather than dissolved solutes in fuel,however,unlikeinanimate particles;microbes can p
4、roliferate or die during the interval between sampling and testing.An important consequence of this is that microbes introduced into the sample from sources otherthan the sample itself,can proliferate and potentially eclipse the population indigenous to the sample.Although microbes can be transporte
5、d in fuel,they require free-water in order to grow andproliferate.Consequently,microbes tend to form colonies that are embedded in hydrophilic matrices.These matrices are most likely to form at system interfaces,including:fuel-water,fuel-structure,bottom-water-structure and air and fuel-vapor to str
6、ucture.Microbes growing within these coloniesproduce chemicals(metabolites and biomolecular detritus)that are deteriogenic(can degrade fuel andfuel system components)and diffuse into fuel.These factors combine to require unique practices specific to the collection of samples that areintended for mic
7、robiological testing.1.Scope*1.1 This practice covers aspects of sample device prepara-tion and sample handling that prevent samples from becomingcontaminated with microorganisms not originally containedwithin the sample.1.2 This practice also covers sample handling consider-ations that reflect the
8、perishability of samples collected formicrobiological testing.1.3 This practice supplements Practice D4057 by providingguidance specific to the manual sampling of fuels whensamples are to be tested for microbial contamination.1.4 The values stated in SI units are to be regarded asstandard.No other u
9、nits of measurement are included in thisstandard.1.5 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 applicab
10、ility of regulatory limitations prior to use.1.6 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 W
11、orld Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D396 Specification for Fuel OilsD910 Specification for Leaded Aviation GasolinesD975 Specification for Diesel FuelD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD1655 S
12、pecification for Aviation Turbine FuelsD2069 Specification for Marine Fuels(Withdrawn 2003)31This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.14 on Stability,Cleanliness and Compatibil
13、ity of Liquid Fuels.Current edition approved May 1,2020.Published June 2020.Originallyapproved in 2008.Last previous edition approved in 2019 as D7464 19.DOI:10.1520/D7464-20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Ann
14、ual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harb
15、or 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 i
16、ssued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.D2880 Specification for Gas Turbine Fuel OilsD3508 Method for Evaluating Water Testing MembraneFilters for Fecal Coliform Recovery(Withdrawn 1995)3D3699 Specification for KerosineD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4814 Specification for Automotive Spark-Ignition EngineFuelD5245 Practice for Cleaning Laboratory Glassware,Plasticware,and Equipment Used in MicrobiologicalAnalysesD6227
