Extech Instruments GX900 User manual

USERGUIDE
TRUERMSINDUSTRIALMULTIMETER
MODELGX900
99 Washington Street
Melrose, MA 02176
Phone [phone]
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com

ExtechInstruments
2 GX900-EU-EN V1.6 4/14
INTRODUCTION
ThankyouforselectingtheExtechModelGX900TrueRMSMultimeterwithhigh
measurementaccuracy,quickA/Dconversionrates,andbuilt‐indataloggingand
trendingfeatures.Thisdeviceisshippedfullytestedandcalibratedand,with
properuse,willprovideyearsofreliableservice.ExtechInstrumentsisanISO‐
9001certifiedcompany.
KEYFEATURES
MeasuresAC/DCVoltageandCurrent(includingremoteClampcurrent),
Resistance,Capacitance,Frequency(electricalandelectronic),RPM,Duty
Cycle,dBm/dBV,Diode,Continuity,andTemperature
Built‐indataloggerandtrendfeaturesstoremeasurementdatawith
convenientrecallfunctionality
Maximumreading(MAX)andMinimumReading(MIN)memoryfeatures
ReadingHOLDfeatureforfreezingdisplayedinformation(withAutoHold)
IntuitiveTFTcolorLCDdisplayandconvenientkeypadpush‐buttoncontrol
On‐screenHELPutilityforuserhintsandapplicationinformation
QuickA/DconversionsamplerateswithlowpassACfiltering
Internalreal‐timecalendarclockfortimestamping
Industrialstrengthmeterhousing
PleasevisittheExtechInstrumentswebsite(www.extech.com)for
thelatestversionsofManuals,Software,Productupdates,and
othercurrentinformation.

ExtechInstruments
3 GX900-EU-EN V1.6 4/14
TABLEOFCONTENTS
INTRODUCTION.......................................................................................2
KEYFEATURES.........................................................................................2
TABLEOFCONTENTS...............................................................................3
SAFETY....................................................................................................6
INTERNATIONALSAFETYSYMBOLS..........................................................6
IEC1010OVERVOLTAGEINSTALLATIONCATEGORIES...............................6
CAUTIONS...............................................................................................7
SAFETYINSTRUCTIONS–INPUTPROTECTIONLIMITS..............................8
FCCCOMPLIANCE....................................................................................9
DESCRIPTIONS.......................................................................................10
METERDESCRIPTION.............................................................................10
INPUTTERMINALDESCRIPTION.............................................................10
KEYPADDESCRIPTION...........................................................................11
LCDDISPLAYDESCRIPTION....................................................................12
QUICKSTARTGUIDE..............................................................................13
MEASUREMENTS...................................................................................14
DCVOLTAGEMEASUREMENTS..............................................................14
ACVOLTAGEMEASUREMENTS..............................................................15
dBm/dBVACMEASUREMENTS..............................................................15
LOWPASSFILTERFORACVMEASUREMENTS........................................16
DC/ACMILLIVOLTMEASUREMENTS......................................................16

ExtechInstruments
4 GX900-EU-EN V1.6 4/14

CURRENTCLAMPMEASUREMENTS.......................................................17
DCCURRENTMEASUREMENTS..............................................................18
ACCURRENTMEASUREMENTS..............................................................19
RESISTANCEMEASUREMENTS...............................................................20
CONTINUITYCHECK...............................................................................21
DIODETEST...........................................................................................21
TEMPERATUREMEASUREMENTS..........................................................22
CAPACITANCEMEASUREMENTS............................................................23
FREQUENCY,DUTYCYCLE,PULSEWIDTH,PERIODMEASUREMENTS....23
RPMMEASUREMENTS...........................................................................24
COUNTERMEASUREMENTS...................................................................24
FUNCTIONSANDFEATURES...................................................................25
FUNCTIONMENUBASICS......................................................................25
THE‘HELP’UTILITY................................................................................25
AUTOMATICANDMANUALRANGING...................................................26
ACANDDCSIGNALS..............................................................................26
MINIMUM(MIN)ANDMAXIMUM(MAX)READINGS............................27
CAPTURINGPEAKVALUES.....................................................................28
RELATIVEMODE....................................................................................28
DATAHOLDANDAUTO‐HOLDMODE....................................................29
STORINGINDIVIDUALSCREEN‐SHOTS...................................................29
VIEWINGMEMORYDATA......................................................................29
VIEWTRENDDATA................................................................................30
RECORDINGMEASUREMENTS(DATALOGGING)....................................31

ExtechInstruments
5 GX900-EU-EN V1.6 4/14

ZOOMINGONTRENDDATA...................................................................32
METERSETUPOPTIONS.........................................................................32
RESETTHEMETERSETUPOPTIONS........................................................32
METERINFORMATIONSCREEN..............................................................33
SETTINGTHEEVENTTHRESHOLDVALUE...............................................33
CHANGECALIBRATIONPASSWORD.......................................................33
CALIBRATIONACCESS............................................................................34
BLUETOOTHTMCAPABILITY....................................................................34
GX900SOFTWARE.................................................................................34
SETTINGTHEDATEANDTIME...............................................................35
AUTOMATICPOWEROFF......................................................................35
TIMEANDDATEFORMATS....................................................................36
NUMERICFORMAT................................................................................36
LANGAUGEFORMAT.............................................................................36
BATTERYANDFUSEREPLACEMENT.......................................................37
BATTERYREPLACEMENT........................................................................37
FUSEREPLACEMENT..............................................................................38
SPECIFICATIONS.....................................................................................39
GENERALSPECIFICATIONS.....................................................................39
ELECTRICALSPECIFICATIONS.................................................................40

ExtechInstruments
6 GX900-EU-EN V1.6 4/14

SAFETY
INTERNATIONALSAFETYSYMBOLS
Thissymbol,adjacenttoanothersymbolorterminal,indicatestheusermust
refertothemanualforfurtherinformation.

Thissymbol,adjacenttoaterminal,indicatesthat,undernormaluse,
hazardousvoltagesmaybepresent

Doubleinsulation

Thissymboladvisestheuserthattheterminalssomarkedmustnotbe
connectedtoacircuitpointatwhichthevoltagewithrespecttoearthground
exceeds(forthisspecificinstrument)1000VACorVDC

WARNINGThissymbolindicatesapotentiallyhazardoussituation,whichifnot
avoided,couldresultindeathorseriousinjury.
CAUTIONThissymbolindicatesapotentiallyhazardoussituation,whichifnot
avoided,couldresultindamagetotheinstrument.
IEC1010OVERVOLTAGEINSTALLATIONCATEGORIES
OVERVOLTAGECATEGORYI
EquipmentofOVERVOLTAGECATEGORYIisequipmentforconnectiontocircuitsinwhich
measuresaretakentolimitthetransientover‐voltagestoanappropriatelowlevel.Examples
includeprotectedelectroniccircuits.
OVERVOLTAGECATEGORYII
EquipmentofOVERVOLTAGECATEGORYIIisenergy‐consumingequipmenttobesuppliedfrom
thefixedinstallation.Examplesincludehousehold,office,andlaboratoryappliances.
OVERVOLTAGECATEGORYIII
EquipmentofOVERVOLTAGECATEGORYIIIisequipmentinfixedinstallations.
Note–Examplesincludeswitchesinthefixedinstallationandsomeequipmentforindustrialuse
withpermanentconnectiontothefixedinstallation.
OVERVOLTAGECATEGORYIV
EquipmentofOVERVOLTAGECATEGORYIVisforuseattheoriginoftheinstallation.Examples
includeelectricitymetersandprimaryover‐currentprotectionequipment.

ExtechInstruments
7 GX900-EU-EN V1.6 4/14

CAUTIONS
Improperuseofthismetercancausedamage,shock,injuryordeath.Readand
understandthisusermanualbeforeoperatingthemeter.
Alwaysremovethetestleadsbeforereplacingthebatteryorfuses.
Inspecttheconditionofthetestleadsandthemeteritselfforanydamagebefore
operatingthemeter.
Usegreatcarewhenmakingmeasurementsifthevoltagesaregreaterthan25VAC
rmsor35VDC.Thesevoltagesareconsideredashockhazard.
Warning!ThisisaclassAequipment.Thisequipmentcancauseinterferencein
residentialareas;inthesecasestheoperatormayberequiredtotakestepsto
avoidorminimizetheinterference.
Alwaysdischargecapacitorsandremovepowerfromthedeviceundertestbefore
performingDiode,Resistance,orContinuitytests.
Voltagechecksonelectricaloutletscanbedifficultandmisleadingbecauseofthe
uncertaintyofconnectiontotherecessedelectricalcontacts.Othermeansshould
beusedtoensurethattheterminalsarenot"live".
Iftheequipmentisusedinamannernotspecifiedbythemanufacturer,the
protectionprovidedbytheequipmentmaybeimpaired.
Thisdeviceisnotatoyandmustnotreachchildren’shands.Itcontainshazardous
objectsaswellassmallpartsthatthechildrencouldswallow.
Donotleavebatteriesandpackingmaterialunattended;theycanbedangerousin
thehandsofchildren.
Intheeventthatthedeviceisgoingtobeunusedforanextendedperiodoftime,
removethebatteries.
Expiredordamagedbatteriescancausecauterizationoncontactwiththeskin.
Always,therefore,usesuitableglovesinsuchcases.
Ensurethatthebatteriesarenotshort‐circuited.Neverincineratebatteries.

ExtechInstruments
8 GX900-EU-EN V1.6 4/14

SAFETYINSTRUCTIONS–INPUTPROTECTIONLIMITS
Thismeterhasbeendesignedforsafeuse,butmustbeoperatedwithcaution.The
ruleslistedinthissafetysectionmustbecarefullyfollowedforsafeoperation.
1. NEVERapplyvoltageorcurrenttothemeterthatexceedsthespecifiedmaximum:
InputProtectionLimits
FunctionMaximumInput
VDCorVAC1000VDC/ACrms
mAAC/DC800mA1000Vfastactingfuse
AAC/DC10A1000Vfastactingfuse
Frequency,Resistance,
Capacitance,DutyCycle,Diode
Test,Continuity
1000VDC/ACrms
Temperature1000VDC/ACrms
2. USEEXTREMECAUTIONwhenworkingwithhighvoltages.
3. DONOTmeasurevoltageifthevoltageonthe"COM"inputjackexceeds1000V
aboveearthground.
4. NEVERconnectthemeterleadsacrossavoltagesourcewhilethefunctionswitchis
inthecurrent,resistance,ordiodemode.Doingsocandamagethemeter.
5. ALWAYSdischargefiltercapacitorsinpowersuppliesanddisconnectthepower
whenmakingresistanceordiodetests.
6. ALWAYSturnoffthepoweranddisconnectthetestleadsbeforeopeningthecovers
toreplacethefuseorbatteries.
7. NEVERoperatethemeterunlessthebackcoverandthebatteryandfusecoversare
inplaceandfastenedsecurely.
8. Iftheequipmentisusedinamannernotspecifiedbythemanufacturer,the
protectionprovidedbytheequipmentmaybeimpaired.



ExtechInstruments
9 GX900-EU-EN V1.6 4/14

FCCCOMPLIANCE
Thisdevicecomplieswithpart15oftheFCCRules.Operationissubjecttothefollowing
twoconditions:

1.Thisdevicemaynotcauseharmfulinterference.
2.Thisdevicemustacceptanyinterferencereceived,includinginterferencethatmay
causeundesiredoperation.

ThisequipmenthasbeentestedandfoundtocomplywiththelimitsforaClassBdigital
device,pursuanttopart15oftheFCCRules.Theselimitsaredesignedtoprovide
reasonableprotectionagainstharmfulinterferenceinaresidentialinstallation.This
equipmentgenerates,uses,andcanradiateradiofrequencyenergyand,ifnotinstalled
andusedinaccordancewiththeinstructions,maycauseharmfulinterferencetoradio
communications.However,thereisnoguaranteethatinterferencewillnotoccurina
particularinstallation.

Ifthisequipmentdoescauseharmfulinterferencetoradioortelevisionreception,which
canbedeterminedbyturningtheequipmentoffandon,theuserisencouragedtotryto
correcttheinterferencebyoneormoreofthefollowingmeasures:

•Reorientorrelocatethereceivingantenna.
•Increasetheseparationbetweentheequipmentandreceiver.
•Connecttheequipmentintoanoutletonacircuitdifferentfromthattowhichthe
receiverisconnected.
•Consultthedealeroranexperiencedradio/TVtechnicianforhelp.


ExtechInstruments
10 GX900-EU-EN V1.6 4/14

DESCRIPTIONS
METERDESCRIPTION
1. LCDdisplay
2. Sub‐functionkeysF1,F2,F3,andF4
3. DataHOLDbutton
4. MAX‐MINmemorybutton
5. RotaryPrimaryFunctionSelectSwitch
6. InputjackforAmperes(A)
7. InputjackmA,uA(milli‐&micro‐Amperes)
8. Inputjack(COM)negative
9. Inputjack(positive)forallfunctions
10. DisplayBacklightcontrol
11. Informationbutton
12. NavigationarrowkeysandOKconfirmationbutton
Note:Batterycompartmentandtiltstandarelocatedontherearoftheinstrument
INPUTTERMINALDESCRIPTION
Allfunctions,exceptingcurrent,usetheVandCOMinputterminals.Separate
terminalsareprovidedforcurrentabove500mAandforcurrentbelow500mA.
Input for 0 A to 10.00 A current
Input for 0 A to 500 mA current measurements
Return terminal for all measurements
Input for voltage, continuity, resistance, diode
test, conductance, capacitance
1
2
3
4
11
10
12
9
5
6
78

ExtechInstruments
11 GX900-EU-EN V1.6 4/14

KEYPADDESCRIPTION
Themeter’s12push‐buttonkeypadactivatesfeatures,augmentsfunctionsselectedby
therotaryswitch,andallowsthenavigationofthedisplayedmenustructure

F1‐F2‐F3‐F4keys
Selectssub‐functionsrelatedtothecurrentlyselectedprimary
modesetbytherotaryswitch

Cursorbuttons
Usethecursorbuttonstoselecteditemsinamenutree,adjust
displaycontrast,scrollinformation,andperformdataentry

HOLDbutton
Freezesthedisplayedreadingand,ifdesired,savesthescreenshot.TheHOLDbutton
alsoaccessestheAUTOHOLDfeaturewhichisdetailedinthisInstructionManual

MAX/MINbutton
StartsandstopstheMaximum(MAX)andMinimum(MIN)readingmemory

OKbutton
Confirmsdataentry

RotarySwitch
Selectstheprimarymeasurementfunction;foreach,themeterpresentsastandard
displayforthatfunction(range,measurementunits,andmodifiers).Seetablebelow:
V~ACvoltagemeasurements
V–DCandAC+DCvoltagemeasurements
mVDC(AC)millivolts,ac+dcmillivolt,Temperature,ClampCurrentmeasurements

Resistance,Diodetest,capacitance,continuitymeasurements
Hz%Frequencyanddutycyclemeasurements
RPMCounterRPM,Countermeasurements
AAC,dcandac+dcampsmeasurements
mAAC,dcandac+dcmilliampsmeasurements
uAAC,dcandac+dcmicroamperemeasurementsupto5,000μA
INFObutton
Openstheinformationwindow
Backlightbutton 
Selectsbacklightintensityfromlowtohigh.Alsousedtoreturnfromanauto‐power
offcondition

ExtechInstruments
12 GX900-EU-EN V1.6 4/14

LCDDISPLAYDESCRIPTION
1. Softkeylabelsindicatethefunctionofthebuttonjustbelowthedisplayedlabel.
2. BargraphAnalogdisplayfortheinputsignal(Seethe"BarGraph"sectionformore
information).
3. Primarymeasurementdisplayarea*(minussignindicatesanegativereading).
4. Rangeindicatesthemeter’spresentrangeandtherangingmode(autoormanual).
5. Batterylevelindicatesthebatterychargelevel.
6. Timeindicatesthetimesetfortheinternalclock.
7. ModeannunciatorsindicatetheMeter'smode.
8. Mini‐measurementdisplayshowstheinputvaluewhentheprimaryandsecondary
displaysarebusywithamenuscreenorpop‐upmessage.Alsoshowsthelightning
bolticon(whennecessary)inthisarea.
9. Maindisplayprovidesmeasurementinformationregardingtheinputsignal.
10. Dateindicatesthedatesetfortheinternalclock.
11. BeeperindicatestheMeter’saudiblefeedbackisenabled(thisisnotassociatedwith
thecontinuitybeeper).
12. Unitindicatestheunitsofmeasure.AuxiliaryUnitsindicatesmeasurementsthatuse
factorsinsteadofunits(suchasCrestFactor).
13. Bluetoothindicatescommunicationlinkactivity.
14. Relativeindicatesthatthedisplayedvalueisrelativetoastoredreferencevalue.
15. Secondarydisplayshowssecondarymeasurementinformationconcerningtheinput
signal.

*ThePrimarydisplayareaindicatesthemostimportantvalueoftheselectedfunction.
Thesecondarydisplaycontainsthebargraphandothervaluesthatmaybemeasuredin
additiontotheprimaryfunction(forexample,frequencymeasurementsalongwiththe
primaryACvoltagemeasurement).

ExtechInstruments
13 GX900-EU-EN V1.6 4/14

QUICKSTARTGUIDE
StepOne:Ensurethatbatteriesareinstalledandarefresh

StepTwo:CarefullyreadtheSafetysectionofthisInstructionManual

StepThree:ChecktheTableofContentstofindthesectionofthisInstruction
Manualrelatedtothedesiredtest

StepFour:Connectthetestleadstothemeterandtothedeviceundertestas
describedinthisInstructionManual’ssectionrelatedtothetestinquestion

StepFive:SafelyperformthetestasdescribedinthisInstructionManual

StepSix:ReadthemeasurementvalueontheLCDdisplay

StepSeven:Carefullydisconnectedthemeter’stestleadsfromthecircuitor
deviceundertest

StepEight:ReadthesectionofthisInstructionManualentitledFeaturesand
Functionstolearnmoreaboutthemultitudeofmeterusesandfeatures

StepNine:Disconnectthetestleadsfromthecircuitundertestandfromthe
meterandswitchOFFthemeterbeforestoring.

ExtechInstruments
14 GX900-EU-EN V1.6 4/14

MEASUREMENTS
WARNING:Riskofelectrocution.High‐voltagecircuits,bothACandDC,areverydangerousandshouldbe
measuredwithgreatcare.
1. ALWAYSturnthefunctionswitchtotheOFFpositionwhenthemeterisnotinuse.
2. IfOLappearsinthedisplayduringameasurement,thevalueexceedstheselected
range.ChangetoahigherrangeorusetheAutorangemode.
DCVOLTAGEMEASUREMENTS
CAUTION:DonotmeasureDCvoltagesifamotoronthecircuitisbeingswitchedONorOFF.Large
voltagesurgesmayoccurthatcandamagethemeter.
1. SetthefunctionswitchtotheV‐position.
2. Inserttheblacktestleadbananaplugintothenegative
COMjack.Inserttheredtestleadbananaplugintothe
positiveVjack.
3. Touchtheblacktestprobetiptothenegativesideofthe
circuit.
4. Touchtheredtestprobetiptothepositivesideofthe
circuit.
5. Readthevoltageinthedisplay.

ExtechInstruments
15 GX900-EU-EN V1.6 4/14

ACVOLTAGEMEASUREMENTS
WARNING:RiskofElectrocution.Theprobetipsmaynotbelongenoughtocontactthelivepartsinside
some240Voutletsforappliancesbecausethecontactsarerecesseddeepintheoutlets.Asaresult,the
readingmayshow0voltswhentheoutletactuallyhasvoltageonit.Makesuretheprobetipsaretouching
themetalcontactsinsidetheoutletbeforeassumingthatnovoltageispresent.
CAUTION:DonotmeasureACvoltagesifamotoronthecircuitisbeingswitchedONorOFF.Largevoltage
surgesmayoccurthatcandamagethemeter.
1. SetthefunctionswitchtotheV~position.
2. Inserttheblacktestleadbananaplugintothenegative
COMjack.Insertredtestleadbananaplugintothe
positiveVjack.
3. Touchtheblacktestprobetiptotheneutralsideofthe
circuit.Touchtheredtestprobetiptothe“hot”sideof
thecircuit.
4. Readthevoltageinthedisplay.
dBm/dBVACMEASUREMENTS
ThemeteriscapableofdisplayingACvoltageasadBvalue;
relativeto1milli‐watt(dBm),relativeto1V(dBV),ortoa
customreferencevalue.
1. SetthefunctionswitchtotheV~position
2. PresstheF1key(MENU)ontheLCDandthen
navigatetothedBm/dBVfieldusingthearrowkeys
andthenpressOK.
3. NavigatetothemenuitemlabeleddBmandthen
pressOK.
4. Inserttheblacktestleadbananaplugintothe
negativeCOMjack.InsertredtestleadbananaplugintothepositiveVjack.
5. Touchtheblacktestprobetiptotheneutralsideofthecircuit.Touchtheredtest
probetiptothe“hot”sideofthecircuit.
6. ReadthedBmintheprimarydisplayareaandreadtheVoltageinthesecondary
displayarea.

ExtechInstruments
16 GX900-EU-EN V1.6 4/14

LOWPASSFILTERFORACVMEASUREMENTS
ThemeterisequippedwithaLowPassFilterforAC
measurements.Toactivatethefilterpleasefollowthesteps
below:
1. SettherotaryswitchtotheV~position
2. PresstheF1key(MENU)
3. MovethemenuselectortotheLOWPASSfieldandthen
pressOK
4. SelectLPF(LowPassFilter)andthenpressOK
5. PresstheF3key(RANGE)andthenpresstheF2key(MANUAL)
6. Movethemenuselectortothe500VfieldandpresstheOKkey
DC/ACMILLIVOLTMEASUREMENTS
CAUTION:DonotmeasureDC/ACvoltagesifamotoronthecircuitisbeingswitchedONorOFF.Large
voltagesurgesmayoccurthatcandamagethemeter.
1. SetthefunctionswitchtothemVposition.
2. PresstheF1key(MENU),movethemenuselectortothemenuitemlabeledmVDC
ormVAC,andthenpresstheOKkey
3. SelectmVDCormVACfromthekeyoptionsandpresstheOKkey.
4. InserttheblacktestleadbananaplugintothenegativeCOMjack.
5. InserttheredtestleadbananaplugintothepositiveVjack.
6. Touchtheblacktestprobetiptothenegativesideofthecircuit.
7. Touchtheredtestprobetiptothepositivesideofthecircuit.
8. Readthevoltageinthedisplay.

ExtechInstruments
17 GX900-EU-EN V1.6 4/14

CURRENTCLAMPMEASUREMENTS
1. Thismeteroffersremotecurrentclampmeasurementfunctionality.
2. SettherotaryswitchtothemVposition.
3. PresstheF1key(MENU),movethemenu
selectortotheitemlabeledCLAMPDC/AC,
andthenpresstheOKkey.
4. SelecttheitemlabeledRANGE
(0.1~100mV/A)andthenpresstheOKkey.
5. Connecttheremoteclamptotheinput
terminaljacksensuringproperpolarity.
Inserttheclamp’snegativeleadintothenegativeCOMjackandconnectthe
clamp’spositiveleadintothemeterspositiveVjack.
6. Readthemeasurementinthedisplay.

ExtechInstruments
18 GX900-EU-EN V1.6 4/14

DCCURRENTMEASUREMENTS
CAUTION:Donotmake20Acurrentmeasurementsforlongerthan30seconds.Exceeding30secondsmay
causedamagetothemeterand/orthetestleads.
1. InsertblacktestleadbananaplugintothenegativeCOMjack.
2. Forcurrentmeasurementsupto5000µADC,setthe
functionswitchtotheµApositionandinserttheredtest
leadbananaplugintotheµA/mAjack.PresstheF1key
(MENU)andselectuADC,PresstheOKkey.
3. Forcurrentmeasurementsupto500mADC,setthefunction
switchtothemApositionandinserttheredtestlead
bananaplugintotheµA/mAjack.PresstheF1key(MENU)
andselectmADC,PresstheOKkey.
4. Forcurrentmeasurementsupto10ADC,setthefunction
switchtothe10Apositionandinserttheredtestlead
bananaplugintothe10Ajack.PresstheF1key(MENU)and
selectADC,PresstheOKkey.
5. Removepowerfromthecircuitundertest,thenopenupthe
circuitatthepointwherecurrentistobemeasured.
6. Touchtheblacktestprobetiptothenegativesideofthe
circuit.
7. Touchtheredtestprobetiptothepositivesideofthe
circuit.
8. Applypowertothecircuit.
9. Readthecurrentinthedisplay.

ExtechInstruments
19 GX900-EU-EN V1.6 4/14

ACCURRENTMEASUREMENTS
CAUTION:Donotmake20Acurrentmeasurementsforlongerthan30seconds.Exceeding30secondsmay
causedamagetothemeterand/orthetestleads.
1. Inserttheblacktestleadbananaplugintothenegative
COMjack.
2. Forcurrentmeasurementsupto5000µAAC,setthe
functionswitchtotheµApositionandinserttheredtest
leadbananaplugintotheµA/mAjack.PresstheF1key
(MENU)andselectuAAC,PresstheOKkey.
3. Forcurrentmeasurementsupto500mAAC,setthe
functionswitchtothemApositionandinserttheredtest
leadbananaplugintotheµA/mAjack.PresstheF1key
(MENU)andselectmAAC,PresstheOKkey.
4. Forcurrentmeasurementsupto10AAC,setthefunction
switchtothe10Apositionandinserttheredtestlead
bananaplugintothe10Ajack.PresstheF1key(MENU)
andselectAAC,PresstheOKkey.
5. PressthekeylabeledMENU,movethemenuselectorto
theitemlabeledAC,andthenpresstheOKkey
6. Removepowerfromthecircuitundertest,thenopenup
thecircuitatthepointwherecurrentistobemeasured.
7. Touchtheblacktestprobetiptotheneutralsideofthecircuit.Touchtheredtest
probetiptothe“hot”sideofthecircuit.
8. Applypowertothecircuit.
9. Readthecurrentinthedisplay.

ExtechInstruments
20 GX900-EU-EN V1.6 4/14

RESISTANCEMEASUREMENTS
WARNING:Toavoidelectricshock,disconnectpowertotheunitundertestanddischargeallcapacitors
beforetakinganyresistancemeasurements.Removethebatteriesandunplugthelinecords.
1. SetthefunctionswitchtotheΩCAPposition.
2. Inserttheblacktestleadbananaplugintothenegative
COMjack.
3. InserttheredtestleadbananaplugintothepositiveΩjack
4. Touchthetestprobetipsacrossthecircuitorpartunder
test.Itisbesttodisconnectonesideofthepartundertest
sotherestofthecircuitwillnotinterferewiththe
resistancereading.
5. Readtheresistanceinthedisplay.