RayTek FA Thermometer User Manual


 
Operation
MarathonSeriesFA/FR 31
Figure27:DeadbandExample
6.2.11AmbientBackgroundTemperatureCompensation(FAModels)
TheFAmodeliscapableofimprovingtheaccuracyoftargettemperaturemeasurementsbytaking
into account the ambient, or background, temperature. This feature is useful when the target
emissivityisbelow1.0andthebackgroundtemperatureisnotsignificantlylowerthanthetarget
temperature.Toutilizethisfeature,youmust
enablethesensorwiththebackgroundtemperature
featureviatheDataTempSoftware.
6.3InputsandOutputs
6.3.1MilliampOutput
Themilliampoutputisananalogoutputyoucanconnectdirectlytoarecordingdevice(e.g.,chart
recorder),PLC,orcontroller.Theanalogoutputresolutionforallmodelsis0.5°Cor1°F.ThemA
outputcanbeforcedtoaspecificvalue,underrange,oroverrangewitha2‐wayRS485command.
Thisfeatureisusefulfortestingorcalibratingconnectedequipment.
6.3.2RelayOutputs
Therelayoutputisusedasanalarmforfailsafeconditionsorasasetpointrelay,refertosection10.2
FailSafeOperation,p.46.RelayoutputsrelatetothecurrentlydisplayedtemperatureontheLED
display.Therelayoutputcanbeusedtoindicateanalarmstateortocontrolexternalactions.The
relaycan besettoeitherNO(NormallyOpen)orNC(NormallyClosed)witha2‐ wayRS485
command(dependingon
thecompatibilityrequirementsofconnectedequipment).Therelaycanbe
forcedonoroffviathe2wayfortestingconnectedequipment.
6.3.3Trigger
PeakHoldandValleyHoldcanbeResetbyshortingtheTriggerinput(labeledTRIG)toGround
(labeledGND)foraminimumof10msec.Thiscanbedoneeitherwithamomentaryswitchorarelay.
BothPeakHoldandValleyHoldhavetobesetto300.0secondsto
recognizethi sReset.TheReset
signalwillcausethepeakorvalleyreadingthatthesensorisholdingtochangeimmediatelytothe
currenttargettemperature.
962°C
958°C
Setpoint: 960°C
Relay Changes State
Time
Normal State Alarm Alarm Normal State
Deadband
Object Temperature