enoeffectsduetoresonancesofthevibrationtableorthemountingstructureinthefrequencyrangespecifiedforthetest.Ifthisisthecase,multipointcontrolmaybenecessary,butseealsoNote3.Ifmorethanfourfixingpointsexist,fourrepresentativefixingpointswillbedefinedintherelevantspecificationtobeusedascheckpoints.NOTE3Inspecialcases,plexspecimens,thecheckpointswillbeprescribedintherelevantspecificationifnotclosetothefixingpoints.NOTE4Wherealargenumberofsmallspecimensaremountedononefixture,orinthecaseofasmallspecimenwherethereareseveralfixingpoints,asinglecheckpoint(i.e.thereferencepoint)maybeselectedforthederivationofthecontrolsignal.Thissignalisthenrelatedtothefixtureratherthantothefixingpointsofthespecimen(s).Thisisonlyvalidwhenthelowestresonancefrequencyoftheloadedfixtureiswellabovetheupperfrequencyofthetest.
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