Designation:D143−22StandardTestMethodsforSmallClearSpecimensofTimber1ThisstandardisissuedunderthefixeddesignationD143;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONTheneedtoclassifywoodspeciesbyevaluatingthephysicalandmechanicalpropertiesofsmallclearspecimenshasalwaysexisted.Becauseofthegreatvarietyofspecies,variabilityofthematerial,continuallychangingconditionsofsupply,manyfactorsaffectingtestresults,andeaseofcomparingvariables,theneedwillundoubtedlycontinuetoexist.Inthepreparationofthesemethodsfortestingsmallclearspecimens,considerationwasgivenbothtothedesirabilityofadoptingtestmethodsthatwouldyieldresultscomparabletothosealreadyavailableandtothepossibilityofembodyingsuchimprovementsasexperiencehasshowndesirable.InviewofthemanythousandsoftestsmadeunderasinglecomprehensiveplanbytheU.S.ForestService,theformerForestProductsLaboratoriesofCanada(nowFPInnovations),andothersimilarorganizations,thesetestmethodsnaturallyconformcloselytothemethodsusedbythoseinstitutions.ThesetestmethodsaretheoutgrowthofastudyofbothAmericanandEuropeanexperienceandmethods.Thegeneraladoptionofthesetestmethodswilltendtowardaworld-wideunificationofresults,permittinganinterchangeandcorrelationofdata,andestablishingthebasisforacumulativebodyoffundamentalinformationonthetimberspeciesoftheworld.Manyofthefiguresinthisstandardusesampledataandcomputationsheetsfromtestingdoneinthe1950sandearlier.Thesefiguresremaininthestandardbecausetheyarestillvaliddepictionsoftherecordingandplottingoftestresultsandalsoprovideahistoricallinktothelargebodyoftestdataonsmallclearspecimensalreadyinexistenceforthislong-standingtestmethod.Descriptionsofsomeofthestrengthtestsrefertoprimarymethodsandsecondarymethods.Primarymethodsprovideforspecimensof2-in.by2-in.(50mmby50mm)crosssection.Thissizeofspecime...
