1、Designation:D2258/D2258M16Standard Practice forSampling Yarn for Testing1This standard is issued under the fixed designation D2258/D2258M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parenthes
2、es indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This practice describes a procedure for the division ofshipments of yarn
3、into test lots and the sampling of such lotsfor testing.1.1.1 This practice can be used for lot sample testing ofyarns for both pre-fabric production and post-fabric produc-tion.1.2 This practice is applicable to single,plied,or cabledyarns,and cords,made of any fiber or mixture of fibers,andsupport
4、ed on any form of package,including beams.1.3 This practice also describes procedures for the samplingof yarn(s)removed from woven or knitted fabrics;however,when thus sampled,the yarns are usually not representative ofentire shipments,as referred to in 1.1.Consequently,theresultant sampling can onl
5、y be used to determine the charac-teristics of the yarn and is usually not used for acceptancetesting.Moreover,it should be recognized that the character-istics of yarns from fabrics may be different than the charac-teristics of the same yarn(s),prior to being entered into thefabric manufacturing pr
6、ocess.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewit
7、h the standard.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.R
8、eferenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1578 Test Method for Breaking Strength of Yarn in SkeinFormD1907 Test Method for Linear Density of Yarn(Yarn Num-ber)by the Skein MethodD4849 Terminology Related to Yarns and Fibers3.Terminology3.1 For terminology related t
9、o Yarns and Fibers,see Termi-nology D4849.3.2 The following terms are relevant to this standard:beam,beam set,bulk sample,case,cone,end,fabric package,laboratory sample,lot,lot sample,primary sampling unit,production lot,sample,sampling unit,sample skein,specimen,and yarn package.3.3 For definitions
10、 of all other textile terms see TerminologyD123.4.Summary of Practice4.1 Instructions are given for dividing the yarn into lots,fordetermining the number of cases,beams,or fabric packages tobe selected from each lot as a lot sample,and for determiningthe number of packages,including the number of en
11、ds,representing those packages taken from the lot sample as alaboratory sample.5.Significance and Use5.1 Assigning a value to any property of the material in acontainer or in a lot,consignment,or delivery involves ameasurement process that includes both sampling and testingprocedures.The correctness
12、 of the value assigned dependsupon the variability due to testing and sampling plan.Even1This practice is under the jurisdiction ofASTM Committee D13 on Textiles andis the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.Current edition approved July 1,2016.Published August 2016.Orig
13、inallyapproved in 1964.Last previous edition approved in 2012 as D2258 99(2012).DOI:10.1520/D2258_D2258M-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
14、 Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 when the variability due to testing is minimized by carefullydeveloped procedures,correct and consistent estimates of thetrue value of the property
15、are possible only when the samplingprocedure avoids systematic bias,minimizes variations due tosampling,and provides a laboratory sample of adequate size.5.2 Practice D2258 may not give the most efficient samplingplan that might be devised in special situations but does presenta general procedure th
16、at gives satisfactory precision with aneconomical amount of sampling.Many plans that includestratified sampling can be found in textbooks and through theuse of statistical software tools and calculators.5.2.1 If not specified by the purchaser,the manufacturer willdefine suitable production lots based on one or more of thefollowing:supply lot,production shift/time segment,produc-tion equipment or production line,operator,designatedshipment,production run,or a combination herein.5.2.2 If not speci
