Teledyne 9060Z - page 43

Model9060ZManual

43

8.2CALIBRATIONMODEFUNCTIONS
8.2.1REFERENCEVOLTAGES
Thecalibrationoftheanalogueinputsisbasedonthevoltageofatemperaturecompensatedvoltage
referenceintegratedcircuit.Thereare4voltagesgeneratedfromthestandardreferencevoltage.
Theywillvarybyabout1%fromonetransmittertoanotherbutcanbetrimmed���bysettingtheactual
voltagesintoCALIBRATIONmenufunctions#1to4.Thesevoltagesshouldbemeasuredandthe
referencevoltageentriesinthemenucheckedeveryyear.
8.2.2OUTPUTCHANNEL1AND2CALIBRATION
Theoutput4‐20mAcalibrationcanbeseteitherAUTOMATICALLY(default)orMANUALLY.IfAuto
Calibratedisselectedthetransmitterwillgothroughanoutputcalibrationcyclewhenthepoweris
turnedonorwhentheAUTOCALbuttonispressedinSETUPmode.Thiswilldiverttheoutputsback
totheinputandautomaticallysetthe4mAand20mAcalibration.
IfManuallyCalibratedisselectedthenthe4mAand20mAcalibrationmustbesetinthenexttwo
functions.Forthefullexplanationseechapter10.1.2.
8.2.3AMBIENTTEMPERATURECALIBRATION
Theambienttemperaturemeasurementisusedasthecoldjunctiontemperatureforthe
thermocouplemeasurements.Useanindependenttemperaturesensortomeasurethetemperature
insidethetransmittercasenearthescrewterminal#1.Enterthistemperatureintothecalibration
function11byusingtheOPTIONkeysandthentheENTERkey.
8.2.4LOWOXYGENCALIBRATION
Thelowoxygencalibrationfactorscanbeusedtofinetunetheoxygencalculationatlowoxygen
readings.Itwillnotaffectthemeasurementat20.9%.Theyareincludedtoallowoxygenprobesmade
byothermanufacturerstobeusedonaTeledyneAnalyticalInstrumentstransmitter.Thedefaultis
100%butcanbesettobetween80and120%.
8.2.5TRANSMITTEROUTPUTSCALE
Thetransmitteroutputscanbeconfiguredtoeither4‐20mAor0‐20mA.Thetwoscaledoutputsare
capableofoutputting0‐24mAandwilltransmitover‐scaleunlesstheover‐scalelimitoptionis
selected.
8.2.6TRANSMITTEROUTPUTLIMITING
Iftheoxygenreadingisinvalidtheoutputcanbemadetobesetto0mA,4mAor20mA.Aninvalid
readingiswhentheprobetemperatureisbelow650°C(1200°F)ortheprobethermocouplehasbeen
detectedasopencircuit.Thedefaultistosettheoutputto20mAbutthefunctioncanalsobe
disabled.
8.2.7MAINSVOLTAGEDETECTION
Thedefaultsettingforthe9060Ztransmitteristhatitwillautomaticallydetectthemainsvoltageand
frequencyinordertocorrectlydrivetheprobeheaters.Ifthereisanyuncertaintyinthisdetection
systemthevoltagecanbeforcedto220‐240or100‐127,andthefrequencycanbesetto50or60Hz.
