Designation:D2168−10(Reapproved2018)StandardPracticesforCalibrationofLaboratoryMechanical-RammerSoilCompactors1ThisstandardisissuedunderthefixeddesignationD2168;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thesepracticesforthecalibrationofmechanicalsoilcompactorsareforuseincheckingandadjustingmechanicaldevicesusedinlaboratorycompactingofsoilandsoil-aggregateinaccordancewithTestMethodsD698,D1557,PracticeD6026,andothermethodsofasimilarnaturethatmightspecifythesepractices.Calibrationforusewithonepracticedoesnotqualifytheequipmentforusewithanotherpractice.1.2Theweightofthemechanicalrammerisadjustedasdescribedin5.4and6.5inordertoprovideforthemechanicalcompactortoproducethesameresultasthemanualcompactor.1.3Twoalternativeproceduresareprovidedasfollows:SectionPracticeACalibrationbasedonthecompactionofaselectedsoilsample5PracticeBCalibrationbasedonthedeformationofastandardleadcylinder61.4IfamechanicalcompactoriscalibratedinaccordancewiththerequirementsofeitherPracticeAorPracticeB,itisnotnecessaryforthemechanicalcompactortomeettherequirementsoftheotherpractice.1.5Thevaluesstatedininch-poundunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.5.1Itiscommonpracticeintheengineeringprofessiontoconcurrentlyusepoundstorepresentbothaunitofmass(lbm)andaforce(lbf).Thisimplicitlycombinestwoseparatesystemsofunits;thatis,theabsolutesystemandthegravita-tionalsystem.Itisscientificallyundesirabletocombinetheuseoftwoseparatesetsofinch-poundunitswithinasinglestandard.Thisstandardhasbeenwrittenusingthegravitationalsystemofunitswhendealingwiththeinch-poundsystem.Inthissystem,thepound(lbf)representsaunitofforce(weight).However,theuseofbalancesorscalesrecordingpoundsofmass...
