Designation:E2561−07a(Reapproved2012)StandardPracticefortheInstallationofInductiveLoopDetectors1ThisstandardisissuedunderthefixeddesignationE2561;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticedescribestherecommendedprocedureforinstallinginductiveloopdetectorsinsawedslotsinroadwaypavementforuseasatrafficmonitoringdeviceortoactuatetrafficcontroldevicessuchasatrafficsignal.Althoughthepracticeisnotintendedforinstallingpreformedloops,thepracticedoescontaininformationofvalueforthistypeofloopsuchasrecommendationsforthenumberofturnsofloopwire,numberanddirectionoftwistsinthelead-inwireandcable,splicelocation(ifneeded),andgroundingoptions.1.2Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesandtodeterminetheapplicabilityofregulatorylimitationspriortouse.2.Terminology2.1DefinitionsofTermsSpecifictoThisStandard:2.1.1electronicsunit,n—acardorfree-standingmodulethattransmitsenergyintothewireloopstypicallyatfrequen-ciesbetween20kHzand100kHz;specialapplicationssuchasvehicleclassificationmayuseelectronicsunitsthattransmitatfrequenciesabove100kHz;electronicsunitsallowcontrolofsensitivity,frequency,pulseorpresenceoperation,andtimingfeatures(thatis,delayandextension)insomemodelsandindicatesystemfailures.2.1.2inductance,n—propertyofanelectriccircuitoroftwoneighboringcircuitsthatgeneratesanelectromotiveforceinonecircuitwhenthecurrentchangesinthatcircuitorintheneighboringcircuit;expressedinunitsofHenrys(H).2.1.3inductiveloopdetector,n—thosepartsofan...
