Designation:E1124−10StandardTestMethodforFieldMeasurementofSoundPowerLevelbytheTwo-SurfaceMethod1ThisstandardisissuedunderthefixeddesignationE1124;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthefield,orinsitumeasurementofsoundpowerlevelbythetwo-surfacemethod.Thetestmethodisdesignedtominimizetheeffectsofreverberantconditions,directivityofthenoisesourceunderconsideration,andtheeffectsofambientnoisefromothernearbyequipmentoperatingatthesametime.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2C634TerminologyRelatingtoBuildingandEnvironmentalAcoustics2.2ANSIStandard:3S1.4SpecificationforSoundLevelMeters3.Terminology3.1Definitions—Fordefinitionsoftermsusedinthistestmethod,refertoTerminologyC634.43.2DefinitionsofTermsSpecifictoThisStandard:3.2.1conformalsurface—thelocusofpointswhichlieatafixeddistancefromthereferencesurfaceofapieceofequipment.Twoconformalsurfacesareusedinthistestmethod.Thesearesurfacesoverwhichthemeasuringmicro-phonesareswept.Theyarelocatedattwodifferentdistancesfromtheequipment.Fig.1showsatypicalarrangementofthesesurfacesforageneralizedpieceofequipment.3.2.2constituentsurfacearea—aportionoftheconformalsurface.4.SummaryofTestMethod4.1Theaverageone-thirdorfulloctavebandsoundpres-surelevelsaremeasuredovertwodifferentconformalsurfaceswhichenveloptheequipment.Theseconformalsurfacesshouldbeselectedtoconsistofrectangular,cylindrical,andhemisphericalconstituentsurfacessothatthesurfaceareasmaybeeasilycalculated.Fromthedifferencebetweenthetwoaveragesoundpressurelevelstakenateachsurfaceandfro...
