Designation:D2905–97(Reapproved2002)StandardPracticeforStatementsonNumberofSpecimensforTextiles1ThisstandardisissuedunderthefixeddesignationD2905;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticeprovidesamechanismforcalculatingthenumberofspecimensperlaboratorysamplingunit.Italsoprovidesrecommendedtextstobeusedinexceptionalcases.Ordinarily,itispreferabletospecifyinthesectiononsamplingasmallfixednumberofspecimensforeachlaboratorysam-plingunit.Occasionally,however,thetaskgroupwritingatestmethodmaythinkthatthevariabilityamongtheobservationsonspecimenswithinalaboratorysamplingunitwillprobablydiffersignificantlyfromlaboratorytolaboratory.Itisinunusualcasesofthissortthattherecommendedtextsinthispracticeshouldbeused.1.1.1ParagraphA14.8oftheRecommendationsonFormandStylespecifiesthatstatementsonthenumberofspecimensbeincludedinalltestmethods.1.2Thispracticecoverssixoptionalrecommendedtextswhichserveasguidesforthepreparationofstatementsonthenumberofspecimensrequiredtodeterminetheaveragequalityofeachunitofthelaboratorysampleundervariousconditions.Thechoiceofthetexttobeusedinaspecificmethodwilldependonthepurposeofthetestandtheavailableinformation.Thispracticecoversthefollowingsixdifferentconditions.Recom-mendedTextConditionsSections1StandardDeviationwithTwo-sidedLimits10,112StandardDeviationwithOne-sidedLimits13,143CoefficientofVariationwithTwo-sidedLimits16,174CoefficientofVariationwithOne-sidedLimits19,205VariabilityKnown,FixedNumberofSpecimens226VariabilityNotKnown,FixedNumberofSpeci-mens241.3RecommendedTexts1through4areprecededbyexamples.Eachexamplestatespartofthedatafromaninterlaboratorytestandillustratesthedecisionsneededinthecourseofcalculatingthenumericalvaluesrequiredforinclu-sioninaspecifictext.Eachofthesetextsdescribestwoconditions:(1)thepr...
