Designation:F1491–93(Reapproved2002)StandardSpecificationforAnAvalancheBeaconFrequency1ThisstandardisissuedunderthefixeddesignationF1491;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThisspecificationestablishesaNationalAvalancheBeaconFrequency.2.Terminology2.1DefinitionsofTermsSpecifictoThisStandard:2.1.1avalanchebeacon—anelectronicdeviceforradiolocationofpersonsburiedortrapped,usuallybysnow,andemployingradiofrequencyelectromagneticinduction.3.Requirements3.1StandardFrequency—Theavalanchebeaconshallop-erateonafrequencyof457.0kHz.3.2AdditionalInterimFrequency—Theavalanchebeaconmayalsooperateonafrequencyof2.275kHz.3.3FrequencyPriorities—Thestandardfrequency(457.0kHz)ismandatoryinalldevices.Useoftheinterimfrequency(2.275kHz)shallnotimpairordisableeffectiveoperationwiththestandardfrequency.3.4TransitiontoStandardFrequency—Bothfrequenciesshouldbeemployedduringtheinterimperiod.Incorporationoftheinterimfrequencyisintendedtoprovidetemporaryback-wardinteroperabilitywitholderbeacons,untilsuchdevicescanbereplacedorretired.Beaconsincorporatingbothfrequen-ciesshouldbeemployeduntilDecember31,1995.Afterthisdate,onlysinglefrequency(457.0kHz)beaconsshouldbeemployedandtheuseof2.275(kHz)shouldbediscontinued.4.SignificanceandUse4.1Avalanchebeaconsareusedforthelocationofpersonswhoareburiedbyavalanches.Inoperation,userswearthebeacons,whichareallsettotransmit.Afteranincident,therescuersswitchtheirunitstoreceiveandsearchforthesubject,whoseunitsarestillintransmit.5.Keywords5.1avalanche;beacon;frequency;snow;transceiverASTMInternationaltakesnopositionrespectingthevalidityofanypatentrightsassertedinconnectionwithanyitemmentionedinthisstandard.Usersofthisstandardareexpresslyadvisedthatdeterminationofthevalidityofanysuchpatentrights,andtheriskofinfringementofsuchrights...
