Mastech MY-65 User manual

MY-65 41/2-DIGITDIGITALMULTIMETER
UsersManual
ReadtheUsersManual thoroughlybeforeuse.
WARRANTY
Thisinstrument iswarrantedtobefreefromdefectsin materialandworkmanshipforaperiod of
oneyear.Anyinstrumentfound defectivewithinoneyearfromthedeliverydateandreturnedto
thefactorywithtransportation chargesprepaid,will berepaired,adjusted,orreplacedatno charge
to theoriginalpurchaser. Thiswarrantydoes not coverexpandableitemssuchasbatteries orfuses.
Ifthedefecthas beencausedbyamisuseorabnormaloperatingconditions,therepairwillbe
billedatanominal cost.
SAFETYINFORMATION
UT30Bdigitalmultimeterhas beendesignedaccordingtoIEC-1010concerning electronic
measuringinstrumentswithanovervoltagecategory(CAT )andpollution2.
Full compliance withsafetystandardscanbeguaranteedonlywithtestleadssupplied.Ifnecessary,
theymust bereplacedwiththetypespecifiedinthemanual.
ELECTRICALSYMBOLS
AC(Alternating Current)
DC(Direct Current)
Importantsafetyinformation.Referto themanual.
Dangerousvoltagemaybepresent.
Earth ground
Fuse
ConformstoEuropeanUniondirectives
Doubleinsulated
WARNING
Toavoid possibleelectricshockorpersonalinjury,follow theseguidelines:
l Donot usethemeterifit isdamaged.Beforeyouusethemeter,inspectthecase.Pay
particularattentionto theinsulationsurroundingtheconnectors
l Inspectthetestleadsfordamagedinsulation orexposedmetal. Checkthetestleadsfor
continuity. Replace damagedtest leadsbeforeyou usethemeter.
l Donot use themeterifitoperates abnormally.Protection maybeimpaired.Whenindoubt,
havethemeterserviced.
l Donotoperatethemeteraroundexplosivegas, vapor, ordust.
l Donotapplymorethantheratedvoltage,as markedon themeter,betweenterminalsor
betweenanyterminalandearth ground.
l Beforeuse, verifythemeter soperation bymeasuringaknown voltage.
l Whenservicing themeter,use onlyspecifiedreplacement parts.
l Use withcaution whenworking above30Vac rms, 42V peak,or60Vdc.Suchvoltages pose
ashockhazard.
l Whenusing theprobes,keepyourfingersbehindthefingerguardsontheprobes.
l Connectthecommontestleadbeforeyouconnectthelivetestlead.Whenyoudisconnect
testleads,disconnect thelivetestleadfirst.

l Removethetestleadsfromthemeterbeforeyou openthebatterydoor.
l Donotoperatethemeterwith thebatterydoororportionsofthecoverremovedorloosened.
l Toavoidfalsereadings,whichcouldleadtopossible electricshockorpersonalinjury,
replacethebatteries as soon as thelow batteryindicator( )appears.
CAUTION
Toavoid possibledamageto themeterorto theequipmentundertest, follow these guidelines:
l Disconnectcircuitpoweranddischargeall high-voltagecapacitorsbeforetesting resistance,
continuity, diodes, orcapacitance.
l Use theproperterminals,function,andrangeforyourmeasurements.
l Beforemeasuring current,checkthemeter sfuses andturnpowerOFFtothecircuit before
connecting themeterto thecircuit.
l Beforerotatingtherangeswitchtochangefunctions,disconnecttestleadsfromthecircuit
undertest.
l Beforeattemptingtoinserttransistorsfortesting,alwaysbesurethatthetest leadshavebeen
disconnectedfromanymeasurement circuits.
MAINTENANCE
l Beforeopening thecase,alwaysdisconnect thetest leadsfromall livecircuits.
l Forcontinueprotectionagainstfire,replace fuse onlywith thespecifiedvoltageandcurrent
ratings:F250mA/250V(Fast Blown)
l Periodicallywipethecase withadampclothandmilddetergent.Donotuse abrasivesor
solvents.
INTRODUCTION
MY-65 Digital Multimeterisahandheld41/2-digit LCDdigitalmultimeterwiththeadvantages of
precisionreadingand stableperformanceetc.,and canbeusedforthe measurement ofDC voltage,
ACvoltage,DCcurrent,ACcurrent,resistance,capacitance, diode,frequencyandcontinuity.It is
anideal instrument foruse inthefield, laboratory,workshop,and home.
FRONTPANEL
1.Powerswitch
2.LCD
3.Input jack
GENERALSPECIFICATIONS
l Display:33/4-digit LCD,Max. reading 3999
l Automaticpolarityindication, “-”displayedfornegativepolarity
l Automaticover-rangeindicationwith figure “1”displayed

l Auto power-off
l Operatingtemperature:0℃～50℃
l Storagetemperature:-40℃～60℃
l Low batteryindication: symbol “”displayedontheupperleft oftheLCD.
l Dimensions:70(W)×155(L)×39(H)mm
l Weight:approx. 250g
SPECIFICATIONS
Accuracyisspecifiedforaperiodof oneyearaftercalibrationandat18℃～28℃with relative
humidityto75%.
Accuracyspecificationstaketheformof:
±([%ofReading]+[numberofLeast Significant Digits])
DC VOLTAGE
RangeResolution Accuracy
200mV0.01mV ±(0.05%+3)
2V 0.1mV ±(0.1%+3)
20V1mV ±(0.1%+3)
200V 10mV ±(0.1%+3)
1000V 0.1mV ±(0.15%+5)
Inputimpedance: 10MΩ
Overloadprotection:Range200mV:250Vdcorac rms
Otherranges:700Vrmsor1000Vpeak
AC VOLTAGE
RangeResolution Accuracy(50～60Hz)Accuracy(40～1000Hz)
2V 0.1mV ±(0.5%+10) ±(1.0%+10)
20V 1mV ±(0.6%+10) ±(1.0%+10)
200V10mV ±(0.6%+10) ±(1.0%+10)
700V0.1V ±(0.8%+15) ±(1.2%+15)
InputImpedance: 2MΩ
Overloadprotection:700Vrmsor1000Vpeak
Indication: Average(rmsofsinewave)
DC CURRENT
RangeResolution Accuracy
2mA0.1µA ±(0.5%+5)
20mA1µA ±(0.5%+5)
200mA10µA ±(0.8%+5)
10A 1mA ±(2.0%+10)
Overloadprotection:250mA/250Vfused(range10Aunfused)
Max.inputcurrent: 10A(Cannot last formorethan10seconds.)
AC CURRENT
RangeResolution Accuracy
2mA0.1µA ±(0.8%+10)
20mA1µA ±(0.8%+10)

200mA10µA ±(1.2%+10)
10A 1mA ±(2.5%+10)
Overloadprotection:250mA/250Vfused(range10Aunfused)
Max.inputcurrent: 10A(Cannot last formorethan10seconds.)
Frequency:40Hz～1000Hz
Indication: Average(rmsofsinewave)
RESISTANCE
RangeResolution Accuracy
200Ω0.01Ω±(0.5%+10)
2KΩ0.1Ω±(0.3%+5)
20KΩ1Ω±(0.3%+2)
200KΩ10Ω±(0.3%+2)
2MΩ100Ω±(0.3%+2)
20MΩ1KΩ±(0.5%+2)
200MΩ10KΩ±[5.0%(rdg-1000)+10 ]
Overloadprotection:250Vac rms
Note:In range200MΩ,it isnormalthatnumber1000 isdisplayedontheLCDwhenthetest
leadsisshorted,andthenumbermustbesubtractedfromthereadingwhilemakingmeasurement.
CAPACITANCE
RangeResolution Accuracy
2000pF0.1pF ±(4.0%+10)
20nF1pF ±(4.0%+10)
200nF10pF ±(4.0%+10)
2µF100pF ±(4.0%+10)
20µF1nF ±(4.0%+10)
FREQUENCY
RangeResolution Accuracy
20KHz1Hz ±(1.5%+5)
Overloadprotection:250Vac rms
Inputvoltage:200mV～10Vrms
AUDIBLE CONTINUITY
RangeDescription
Iftheresistanceundermeasurement isless 70Ω,thebuilt-inbuzzerwill
sound.
OPERATINGINSTRUCTION
MEASURINGVOLTAGE
1.Connect theblacktestleadtothe “COM”jackandtheredtestleadto the “VΩHz”jack.
2.Settherotaryswitchto thedesiredV~orV rangeandconnectthetestleadstothesource

orloadto bemeasured.
3.Whenonlythefigure “1”isdisplayedon theLCD,it indicates that thevoltageunder
measurement isover-rangeandtherotaryswitchmust besetto higherrange.
MEASURINGCURRENT
1.Connect theblacktestleadtothe “COM”jackandtheredtestleadto the “mA”jackforthe
current upto200mAorto the “A”jackforthecurrentbetween200mAand 20A.
2.Settherotaryswitchto thedesiredA~orA rangeandconnectthetestleadsinseries with
theloadundermeasurement.
Thepolarityoftheredleadconnection will bedisplayedalongwith thecurrent valuewhen
making DCcurrentmeasurement.
3.Whenonlyfigure “1”isdisplayed, it indicates thecurrent undermeasurementisover-range
and therotaryswitchmustbesettohigherrange.
MEASURINGFREQUENCY
1.Connect theblacktestleadtothe “COM”jackandtheredtestleadto the “VΩHz”jack.
2.Settherotaryswitchto the “20KHz”rangeand connectthetestleadsto thesource orload
undermeasurement.
NOTE:
l Iftheinput voltageisabove10Vrms,youmayreadthefrequencyfromtheLCD,but
theaccuracyofthereading isnotguaranteed.
l It isbettertouse shieldcableformeasuringsmall signalto avoidinterference.
MEASURINGRESISTANCE
1.Connect theredtest leadtothe “VΩHz”jackand theblacktestleadtothe “COM”jack.
2.Settherotaryswitchto thedesired Ωrange.
3.Connect thetest leadstotheresistorto bemeasuredand readthevaluedisplayedontheLCD.
4.Whilemeasuringin-circuitresistance,disconnectedcircuit poweranddischargeall
high-voltagecapacitorsbeforemeasuring.
MEASURINGCAPACITANCE
1.Settherotaryswitchto thedesiredFrange.
2.Beforeinsertingthecapacitortobemeasuredintothecapacitancetestingsocket, besurethat
thecapacitorhas beenfullydischarged.
3.Whenmeasuringcapacitorswithshorterleads,atestingadapterisprovidedwith themeter.
Inserttheadapterintothecapacitance testingsocketonthefront paneltocontinuethe
measurement.
WARNING
Toavoidelectricshock,besurethecapacitormeasuring adapterhas beenremovedbefore
changing toanotherrange.
TESTINGDIODE
1.Connect theblacktestleadtothe “COM”jackandtheredtestleadto the “VΩHz”jack.
2.Settherotaryswitchtothe “”rangeandconnecttheredtestleadtotheanodeof the
diodetobetestedandtheblacktestleadtothecathodeof it. Themeterwillshowtheapprox.
forwardvoltagedrop ofthediode.Iftheconnection isreversed,onlyfigure “1”willbe
displayed.
TESTINGTRANSISTOR
1.Settherotaryswitchto the “hFE”range.

2.DeterminewhetherthetransistortobetestedisNPNorPNP,andlocatetheE,BandCleads.
Inserttheleadsofthetransistorintotheirproperholes ofthetransistortestingsocket.
3.Themeterwillshow theapprox.hFEvalueatthetestcondition ofIb≈10μAandVce≈
3.2V.
CONTINUITYTEST
1.Connect theblacktestleadtothe “COM”jackandtheredtestleadto the “VΩHz”jack.
2.Settherotaryswitchto “ ” rangeandconnectthetestleadstothetwoterminalsofthe
circuit tobetested. If theresistance isless thanabout70Ω, thebuilt-in buzzerwillsound.
Battery&Fuse Replacement
If “”appearson theLCD,it indicates thatthebatteryshouldbereplaced.Toreplacethe
battery,openthecaseandreplacetheexhaustedbatterywith theratingsspecified: 9V,NEDA
1604 or6F22.
Thefuserarelyneedstobereplacedandisblownas aresult oftheoperator serror. Toreplace the
fuse,openthecase andreplace theblownfusewith theratingsspecified: F250mA/250V.
Toreplace batteryorfuse,removethe2screwsinthebottomofthecaseand openthecase.
Replacethebatteryorfuse withanewoneofthesame rating.Close case andtightenscrews
completely.
ACCESSORIES
UsersManual1copy
TestLeads1pair
9VBattery(NEDA1604or6FF22) 1piece