Designation:G165−99(Reapproved2012)StandardPracticeforDeterminingRail-to-EarthResistance1ThisstandardisissuedunderthefixeddesignationG165;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoverstheproceduresnecessarytofollowformeasuringresistance-to-earthoftherunningrailswhichareusedastheconductorsforreturningthetrainoperatingcurrenttothesubstationinelectricmasstransitsystems.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2G15TerminologyRelatingtoCorrosionandCorrosionTest-ing(Withdrawn2010)33.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1crossbond—insulatedcoppercablesthatconnectedbetweenadjacentsectionsoftracktoensureelectricalconti-nuitybetweenthem.3.1.2directfixationfastener—adeviceforfasteningrunningrailstotheirsupportstructures.3.1.3impedancebond—adeviceconnectedtorunningrailsforautomatictrainoperations.3.1.4Theterminologyusedherein,ifnotspecificallyde-finedotherwise,shallbeinaccordancewithTerminologyG15.Definitionsprovidedherein,andnotgiveninTerminologyG15,arelimitedtothispractice.4.SignificanceandUse4.1Lowresistancebetweentherailsandearthcouldresultinlargemagnitudesofstrayearthcurrentswiththeattendantcorrosiondamagetoundergroundmetallicstructures.4.2Thesemeasurementsareofalowvoltagetypeandarenotdesignedtoevaluatethehighvoltagedielectriccharacter-isticsoftherailinsulatingelements.4.3Sectionsoftrackwithrail-to-earthresistanceslessthanacceptableminimumsmustbetestedingreaterdetailtodete...
