ABCs of Multimeter Safety

Application Note

ABCs ofMultimeter Safety

Multimeter safety and you

Voltage spikes–anunavoidable hazardAs distribution systems andloads become more complex,the possibilities of transientovervoltages increase. Motors,capacitors and power conver-sion equipment such as variablespeed drives can be prime gen-erators of spikes. Lightningstrikes on outdoor transmissionlines also cause extremely haz-ardous high-energy transients.If you’re taking measurementson electrical systems, thesetransients are “invisible” andlargely unavoidable hazards.They occur regularly on low-voltage power circuits, and canreach peak values in the manythousands of volts. In thesecases, you’re dependent for pro-tection on the safety marginalready built into your meter.The voltage rating alone willnot tell you how well that meterwas designed to survive hightransient impulses.

Early clues about the safetyhazard posed by spikes camefrom applications involvingmeasurements on the supplybus of electric commuter rail-roads. The nominal bus voltagewas only 600V, but multimetersrated at 1000V lasted only afew minutes when takingmeasurements while the trainwas operating. A close lookrevealed that the train stoppingand starting generated 10,000Vspikes. These transients hadno mercy on early multimeterinput circuits. The lessonslearned through this investiga-tion led to significant improve-ments in multimeter inputprotection circuits.

New safety standardsTo protect you against tran-sients, safety must be built intothe test equipment. What per-formance specification shouldyou look for, especially if youknow that you could be work-ing on high-energy circuits?The task of defining a newspecification for test equipmentwas recently addressed by theIEC (International Electro-technical Commission). Thisorganization develops interna-tional safety standards forelectrical test equipment.

For a number of years theindustry standard was IEC 348.That standard has beenreplaced by IEC 61010. Whilewell-designed IEC 348 metershave been used for years bytechnicians and electricians,the fact is that meters designedto the new IEC 61010 standardoffer a significantly higher levelof safety. Let’s see how this isaccomplished.

1000VCAT III

Designed and Conforms to

IEC 1010-1

yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

100ms AVG H

k

400 1 2 3 54 6 7 8 9 0

87 TRUE RMS MULTIMETER

MIN MAX RANGE HOLD H

REL Hz

mAA

A

mV

V

V

OFF

!

A COM VmA A

1000V MAX

400mA MAXFUSED

10A MAXFUSED

PEAK MIN MAX

AC

V

40V

0 1 2 3 54 6 7 8 9 0

Don’t overlook safety–your life may depend on itWhere safety is a concern,choosing a multimeter is likechoosing a motorcycle helmet–if you have a “ten-dollar” head,choose a “ten-dollar” helmet. Ifyou value your head, get a safehelmet. The hazards of motor-cycle riding are obvious, butwhat’s the issue withmultimeters? As long as youchoose a multimeter with ahigh-enough voltage rating,aren’t you safe? Voltage isvoltage, isn’t it?

Not exactly. Engineers whoanalyze multimeter safety oftendiscover that failed units weresubjected to a much higher volt-age than the user thought hewas measuring. There are theoccasional accidents when themeter, rated for low voltage(1000V or less), was used tomeasure medium voltage, suchas 4160V. Just as common, theknock-out blow had nothing todo with misuse–it was a mo-mentary high-voltage spike ortransient that hit the multimeterinput without warning.

2 Fluke Corporation ABCs of Multimeter Safety

Transient protectionThe real issue for multimetercircuit protection is not just themaximum steady state voltagerange, but a combination of bothsteady state and transient over-voltage withstand capability.Transient protection is vital.When transients ride on high-energy circuits, they tend to bemore dangerous because thesecircuits can deliver large cur-rents. If a transient causes anarc-over, the high current cansustain the arc, producing aplasma breakdown or explosion,which occurs when the sur-rounding air becomes ionizedand conductive. The result is anarc blast, a disastrous eventwhich causes more electrical in-juries every year than the betterknown hazard of electric shock.(See “Transients–the HiddenDanger” on page 4.)

Overvoltage installationcategoriesThe most important single con-cept to understand about thenew standards is the Overvolt-age Installation Category. Thenew standard defines CategoriesI through IV, often abbreviatedas CAT I, CAT II, etc. (See Figure1.) The division of a power dis-tribution system into categoriesis based on the fact that a dan-gerous high-energy transientsuch as a lightning strike will beattenuated or dampened as ittravels through the impedance(ac resistance) of the system.A higher CAT number refers toan electrical environment withhigher power available andhigher-energy transients. Thus amultimeter designed to a CAT IIIstandard is resistant to muchhigher-energy transientsthan one designed to CAT IIstandards.

Within a category, a highervoltage rating denotes a highertransient withstand rating: e.g.,a CAT III-1000V meter has supe-rior protection compared to aCAT III-600V rated meter. Thereal misunderstanding occurs ifsomeone selects a CAT II-1000Vrated meter thinking that it issuperior to a CAT III-600Vmeter. (See “When is 600Vmore than 1000V?” on page 7.)

Figure 1. Location, location, location.

Understanding categories: Location, location,

Table 1. Overvoltage installation categories. IEC 61010 applies to low-voltage (<1000V) test equipment.

CAT IV Three-phaseat utilityconnection,any outdoorsconductors

• Refers to the “origin of installation”, i.e., where low-voltageconnection is made to utility power.

• Electricity meters, primary overcurrent protection equipment.• Outside and service entrance, service drop from pole

to building, run between meter and panel.• Overhead line to detached building, underground line

to well pump.

CAT III Three-phasedistribution,includingsingle-phasecommerciallighting

• Equipment in fixed installations, such as switchgear andpolyphase motors.

• Bus and feeder in industrial plants.• Feeders and short branch circuits, distribution panel devices.• Lighting systems in larger buildings.• Appliance outlets with short connections to service

entrance.

CAT II Single-phasereceptacleconnectedloads

• Appliance, portable tools, and other household and similarloads.

• Outlet and long branch circuits.• Outlets at more than 10 meters (30 feet) from CAT III source.• Outlets at more that 20 meters (60 feet) from CAT IV source.

CAT I Electronic • Protected electronic equipment.• Equipment connected to (source) circuits in which measures

are taken to limit transient overvoltages to an appropriatelylow level.

• Any high-voltage, low-energy source derived from a high-winding resistance transformer, such as the high-voltagesection of a copier.

OvervoltageCategory In Brief Examples

ABCs of Multimeter Safety Fluke Corporation 3

What does theCE symbol indicate?A product is marked CE(Conformité Européenne)to indicate its conformance tocertain essential requirementsconcerning health, safety,environment and consumerprotection established by theEuropean Commission andmandated through the use of“directives.” There are directivesaffecting many product types,and products from outside theEuropean Union can not beimported and sold there if theydo not comply with applicabledirectives. Compliance with thedirective can be achieved byproving conformance to arelevant technical standard,such as IEC 61010 for lowvoltage products. Manufacturersare permitted to self-certify thatthey have met the standards,issue their own Declarationof Conformity, and mark theproduct “CE.” The CE markis not, therefore, a guaranteeof independent testing.

location…

It’s not just thevoltage levelIn Figure 1, a technician work-ing on office equipment in aCAT I location could actuallyencounter dc voltages muchhigher than the power line acvoltages measured by the motorelectrician in the CAT III loca-tion. Yet transients in CAT Ielectronic circuitry, whateverthe voltage, are clearly a lesserthreat, because the energyavailable to an arc is quite lim-ited. This does not mean thatthere is no electrical hazardpresent in CAT I or CAT II equip-ment. The primary hazard iselectric shock, not transientsand arc blast. Shocks, whichwill be discussed later, can beevery bit as lethal as arc blast.

To cite another example, anoverhead line run from a houseto a detached workshed mightbe only 120V or 240V, but it’sstill technically CAT IV. Why?Any outdoor conductor is sub-ject to very high-energy light-ning-related transients. Evenconductors buried undergroundare CAT IV, because althoughthey will not be directly struckby lightning, a lightning strikenearby can induce a transientbecause of the presence of highelectro-magnetic fields.

When it comes to Overvolt-age Installation Categories, therules of real estate apply: it’slocation, location, location...(For more discussion of InstallationCategories, see page 6, “Applyingcategories to your work.”)

Independent testing is thekey to safety complianceLook for a symbol and listingnumber of an independent test-ing lab such as UL, CSA, TÜV orother recognized testing organi-zation. Beware of wording suchas “Designed to meet specifica-tion ...” Designer’s plans arenever a substitute for an actualindependent test.

How can you tell if you’regetting a genuine CAT III or CATII meter? Unfortunately it’s notalways that easy. It is possiblefor a manufacturer to self-certifythat its meter is CAT II or CAT IIIwithout any independent verifi-cation. The IEC (InternationalElectrotechnical Commission)develops and proposes stan-dards, but it is not responsiblefor enforcing the standards.

Look for the symbol and list-ing number of an independenttesting lab such as UL, CSA, TÜVor other recognized approvalagency. That symbol can onlybe used if the product success-fully completed testing to theagency’s standard, which isbased on national/internationalstandards. UL 3111, for example,is based on IEC 61010. In an im-perfect world, that is the closestyou can come to ensuring thatthe multimeter you choose wasactually tested for safety.

Independent testing


Protection against two major electrical hazards:

Let’s take a look at a worst-casescenario in which a technicianis performing measurementson a live three-phase motorcontrol circuit, using a meterwithout the necessary safetyprecautions.

Here’s what could happen:1. A lightning strike causes a

transient on the power line,which in turn strikes an arcbetween the input terminalsinside the meter. The circuitsand components to preventthis event have just failed orwere missing. Perhaps it wasnot a CAT III rated meter. Theresult is a direct short be-tween the two measurementterminals through the meterand the test leads.

2. A high-fault current–possiblyseveral thousands of amps–flows in the short circuit justcreated. This happens inthousandths of a second.When the arc forms insidethe meter, a very high-pres-sure shock wave can cause

a loud bang!–very much likea gunshot or the backfirefrom a car. At the same in-stant, the tech sees brightblue arc flashes at the testlead tips–the fault currentssuperheat the probe tips,which start to burn away,drawing an arc from thecontact point to the probe.

3. The natural reaction is to pullback, in order to break con-tact with the hot circuit. Butas the tech’s hands arepulled back, an arc is drawnfrom the motor terminal toeach probe. If these two arcsjoin to form a single arc,there is now another directphase-to-phase short, thistime directly between themotor terminals.

4. This arc can have a tempera-ture approaching 6,000°C(10,000°F), which is higherthan the temperature of anoxy-acetylene cutting torch!As the arc grows, fed byavailable short circuit current,it superheats the surroundingair. Both a shock blast and aplasma fireball are created.If the technician is lucky, theshock blast blows him awayand removes him from theproximity of the arc; thoughinjured, his life is saved. Inthe worst case, the victim issubjected to fatal burn inju-ries from the fierce heat ofthe arc or plasma blast.

In addition to using a multi-meter rated for the appropriateOvervoltage Installation Cat-egory, anyone working on livepower circuits should be pro-tected with flame resistantclothing, should wear safetyglasses or, better yet, a safetyface shield, and should useinsulated gloves.

A lightning strike causes a transienton the power line, creating an arcbetween the meter’s input terminaland resulting in loud noises.

Then, a high current flows in theclosed circuit which is formed.An arc starts at the probe tips.

If those arcs join, theresulting high-energyarc can create a life-threatening situationfor the user.

When you pull the probes away,as a reaction to the loud noise,arcs are drawn to the motorterminals you’re probing.

Transients–the hidden danger

4

1

1

2

3

Figure 2. A worst-case scenario—potential arc blast sequence.


Arc blast and electric shock

Transients aren’t the only sourceof possible short circuits and arcblast hazard. One of the mostcommon misuses of handheldmultimeters can cause a similarchain of events.

Let’s say a user is makingcurrent measurements on signalcircuits. The procedure is to se-lect the amps function, insert theleads in the mA or amps inputterminals, open the circuit andtake a series measurement. In aseries circuit, current is alwaysthe same. The input impedanceof the amps circuit must be lowenough so that it doesn’t affectthe series circuit’s current. Theinput impedance on the 10A ter-minal of a Fluke meter is .01Ω.Compare this with the input im-pedance on the voltage termi-nals of 10MΩ (10,000,000Ω).

If the test leads are left in theamps terminals and then acci-dentally connected across a volt-age source, the low input im-pedance becomes a short circuit!It doesn’t matter if the selectordial is turned to volts; the leadsare still physically connected toa low-impedance circuit.* That’swhy the amps terminals must beprotected by fuses. Those fusesare the only thing standing be-tween an inconvenience–blownfuses–and a potential disaster.

Use only a multimeter withamps inputs protected by high-energy fuses. Never replace ablown fuse with the wrong fuse.Use only the high-energy fusesspecified by the manufacturer.These fuses are rated at a volt-age and with a short circuitinterrupting capacity designedfor your safety.

Overload protectionFuses protect againstovercurrent. The high inputimpedance of the volts/ohmsterminals ensures that anovercurrent condition is unlikely,so fuses aren’t necessary. Over-voltage protection, on the otherhand, is required. It is providedby a protection circuit thatclamps high voltages to anacceptable level. In addition, athermal protection circuit detectsan overvoltage condition, pro-tects the meter until the condi-tion is removed, and then auto-matically returns to normaloperation. The most commonbenefit is to protect the multi-meter from overloads when it isin ohms mode. In this way, over-load protection with automaticrecovery is provided for allmeasurement functions as longas the leads are in the voltageinput terminals.

Figure 3. Misuse of DMM in Ammeter Mode.

While most people are awareof the danger from electricshock, few realize how littlecurrent and how low a voltageare required for a fatal shock.Current flows as low as 30 mAcan be fatal (1mA=1/1000A).Let’s look at the effects of cur-rent flow through a “typical”68 kilogram (150 pound) male:• At about 10 mA, muscular

paralysis of the arms occurs,so that he cannot release hisgrip.

• At about 30 mA, respiratoryparalysis occurs. His breath-ing stops and the results areoften fatal.

• At about 75-250 mA, for ex-posure exceeding 5 seconds,ventricular fibrillationoccurs, causing discoordina-tion of the heart muscles;the heart can no longerfunction. Higher currentscause fibrillation at less than5 seconds. The results areoften fatal.

Now let’s calculate the thresh-hold for a “hazardous” voltage.The approximate body resis-tance under the skin fromhand to hand across the bodyis 1000Ω. A voltage of only30V across 1000Ω will cause acurrent flow of 30 mA. Fortu-nately, the skin’s resistance ismuch higher. It is the resis-tance of the skin, especiallythe outer layer of dead cells,called the “horny layer,” thatprotects the body. Under wetconditions, or if there is a cut,skin resistance drops radically.At about 600V, the resistanceof the skin ceases to exist. It ispunctured by the high voltage.

For multimeter manufactur-ers and users, the objective isto prevent accidental contactwith live circuits at all costs.Look for:• Meters and test leads with

double insulation.• Meters with recessed input

jacks and test leads withshrouded input connectors.

• Test leads with fingerguards and a non-slipsurface.

• Meter and test leads madeof high-quality, durable,non-conductive materials.

Use the right high-energy fusesElectric shock

*Some multimeters, such as the Fluke 80 Series, have an Input Alertwhich gives a warning beep if the meter is in this configuration.


Multiple categoriesThere’s one scenario that some-times confuses people trying toapply categories to real worldapplications. In a single pieceof equipment, there is oftenmore than one category. Forexample, in office equipment,from the 120V/240V side of thepower supply back to thereceptacle is CAT II. The elec-tronic circuitry, on the otherhand, is CAT I. In building con-trol systems, such as lightingcontrol panels, or industrial con-trol equipment such as pro-grammable controllers, it iscommon to find electroniccircuits (CAT I) and powercircuits (CAT III) existing inclose proximity.

What do you do in these situ-ations? As in all real-world situ-ations, use common sense. Inthis case, that means using themeter with the higher categoryrating. In fact, it’s not realistic toexpect people to be goingthrough the category-definingprocess all the time. What isrealistic, and highly recom-mended, is to select a multi-meter rated to the highest cat-egory in which it could possiblybe used. In other words, err onthe side of safety.

Shortcuts tounderstanding categoriesHere are some quick ways toapply the concept of categoriesto your every day work:• The general rule-of-thumb is

that the closer you are to thepower source, the higher thecategory number, and thegreater the potential dangerfrom transients.

• It also follows that the greaterthe short-circuit current avail-able at a particular point, thehigher the CAT number.

• Another way of saying thesame thing is the greater thesource impedance, the lowerthe CAT number. Sourceimpedance is simply the totalimpedance, including theimpedance of the wiring,between the point where youare measuring and the powersource. This impedance iswhat dampens transients.

• Finally, if you have any expe-rience with the application ofTVSS (Transient Voltage SurgeSuppression) devices, you un-derstand that a TVSS deviceinstalled at a panel must havehigher energy-handling ca-pacity than one installed rightat the computer. In CAT termi-nology, the panelboard TVSSis a CAT III application, andthe computer is a receptacle-connected load and, therefore,a CAT II installation.

As you can see, the concept ofcategories is not new andexotic. It is simply an extensionof the same common-senseconcepts that people who workwith electricity professionallyapply every day.

Work safely

Safety is everyone’s responsibility butultimately it’s in your hands.

No tool by itself can guarantee yoursafety. It’s the combination of the righttools and safe work practices that givesyou maximum protection. Here are afew tips to help you in your work.• Work on de-energized circuits when-

ever possible. Use proper lock-out/tag-out procedures. If these procedures arenot in place or not enforced, assumethat the circuit is live.

• On live circuits, use protective gear:– Use insulated tools.– Wear safety glasses or a face shield.– Wear insulated gloves; remove

watches or other jewelry.– Stand on an insulated mat.– Wear flame resistant clothing,

not ordinary work clothes.• When making measurements on

live circuits:– Hook on the ground clip first, then

make contact with the hot lead.Remove the hot lead first, theground lead last.

– Hang or rest the meter if possible.Try to avoid holding it in yourhands, to minimize personal expo-sure to the effects of transients.

– Use the three-point test method,especially when checking to see ifa circuit is dead. First, test a knownlive circuit. Second, test the targetcircuit. Third, test the live circuitagain. This verifies that your meterworked properly before and afterthe measurement.

– Use the old electricians’ trick ofkeeping one hand in your pocket.This lessens the chance of a closedcircuit across your chest andthrough your heart.

Applying categories to your work

Use protectiveequipment such assafety glasses andinsulated gloves.


Understanding voltagewithstand ratingsIEC 61010 test procedures takeinto account three main criteria:steady-state voltage, peakimpulse transient voltage andsource impedance. These threecriteria together will tell you amultimeter’s true voltagewithstand value.

When is 600Vmore than 1000V?Table 2 can help us understandan instrument’s true voltagewithstand rating:1. Within a category, a higher

“working voltage” (steady-state voltage) is associatedwith a higher transient, aswould be expected. For ex-ample, a CAT III-600V meteris tested with 6000V tran-sients while a CAT III-1000Vmeter is tested with 8000Vtransients. So far, so good.

2. What is not as obvious is thedifference between the6000V transient for CAT III-600V and the 6000V tran-sient for CAT II-1000V. Theyare not the same. This iswhere the source impedancecomes in. Ohm’s Law (Amps= Volts/Ohms) tells us thatthe 2Ω test source for CAT IIIhas six times the currentof the 12Ω test source forCAT II.

The CAT III-600V meter clearlyoffers superior transient protec-tion compared to the CAT II-1000V meter, even though itsso-called “voltage rating” couldbe perceived as being lower. Itis the combination of thesteady-state voltage (called theworking voltage), and the cat-egory that determines thetotal voltage withstand ratingof the test instrument, includingthe all-important transientvoltage withstand rating.

A note on CAT IV: Test valuesand design standards for Cat-egory IV voltage testing are not

Overvoltage Working Voltage Peak ImpulseInstallation (dc or ac-rms Transient Test SourceCategory to ground) (20 repetitions) (Ω = V/A)

CAT I 600V 2500V 30 Ohm source

CAT I 1000V 4000V 30 Ohm source

CAT II 600V 4000V 12 Ohm source

CAT II 1000V 6000V 12 Ohm source

CAT III 600V 6000V 2 Ohm source

CAT III 1000V 8000V 2 Ohm source

Table 2: Transient test values for overvoltage installation categories.(50/150V/300V values not included.)

How to evaluate a multimeter’s safety rating

presently addressed in IEC61010, but are under consider-ation for the second edition.Therefore the highest-ratedmeters currently available areCAT III-1000V.

Creepage and clearanceIn addition to being tested toan actual overvoltage transientvalue, multimeters are requiredby IEC 61010 to have minimum“creepage” and “clearance” dis-tances between internal com-ponents and circuit nodes.Creepage measures distanceacross a surface. Clearancemeasures distances throughthe air. The higher the categoryand working voltage level, thegreater the internal spacingrequirements. One of the maindifferences between the oldIEC 348 and IEC 61010 is theincreased spacing requirementsin the latter.

The bottom lineIf you are faced with the task ofreplacing your multimeter, doone simple task before you startshopping: analyze the worst-case scenario of your job anddetermine what category youruse or application fits into.

First choose a meter rated forthe highest category you couldbe working in. Then, look for amultimeter with a voltage ratingfor that category matching yourneeds. While you’re at it, don’tforget the test leads. IEC 61010applies to test leads too: theyshould be certified to a categoryand voltage as high or higherthan the meter. When it comesto your personal protection,don’t let test leads be theweak link.

Look for categoryand voltage

ratings of testleads and

multimeters.


RANGE HOLD

1000V CAT600V CAT

FUSED

V40mA

10A COM

40 CAL

V

OFF

Hz

V

A

mV

40

V 1kHzHz 20kHz

Use a meter ratedfor the categoryand voltage whereyou’re working.

• Look for a metercertified by anindependenttesting agency.

• Use only meterswith high-energyfuses on the ampsterminals. Andalways replacefuses with onesrecommended bythe manufacturer.

• Use only test leadsrated to a categoryand voltage as highor higher than themeter.

Use the right multimeter for the job

80 Series III• High-

performanceDMM

• True-rms(Fluke 85 & 87)

Model 12B• V-Chek™ for

quick and safemeasurement ofpower circuits

RANGE MINMAX

OFFV

AUTOMATICSELECTION

600V

LOW IMPEDANCE

COM

CAT

+

12B MULTIMETER

MAX M

VDCVAC

70 Series III20 Series III• Large, high-

contrastdisplay

• Taperedslimline case

• True-rms(Fluke 79-IIIand 26-III)

600V

+COM

7-600 ELECTRICALTESTER

OFF

AUTOMATICSELECTION

V DC

V AC

LOW IMPEDANCECAT

100ms AVG H

k

400 1 2 3 54 6 7 8 9 0


MIN MAX RANGE HOLD H

REL Hz

mAA

A

mV

V

V

OFF

!

A COM VmA A

1000V MAX

400mA MAXFUSED

10A MAXFUSED

PEAK MIN MAX

Model 7-600• Auto selection

of volts (ac ordc) or ohms

CAT III 600VCAT III 1000V

860 Series• World’s most

advancedmultimeter

• New brightwaveformdisplay

Model 31 and 33• AC true-rms

current

• Frequency

• Min/Max/Average, Crest(33)

COMPONENTTEST

SET UP

mV

V

VOFF

LOGIC HiZ

A

1000V MAX

mAAµ COMPONENT

TEST

LOGIC

10A MAX FUSED 1000V MAX 320mA MAX FUSED

CAT ALL INPUTS 1000V MAX

FREEZE

WAKE UP

A COM VmA / µA EXT TRIG

GRAPHICAL MULTIMETER867

SAVEPRINT

MINMAX RANGE

TOUCHHOLD

DISPLAYMODE

Hz

1 2 3 4 5

SEE WARNINGS ON BACK

HOLD

200A600A

200V

OFF

200

600V

600V 600A

32 CLAMP METER

600VCOM V

TRUE RMS

CAT III

CAT III 600V Models 36 and 32 also measure resistance and fast continuity

Model 32• AC current and

voltage

• True-rms

CAT

200A

200V

OFF

200

600V

600A1000A

MAX

600V 600A

1000A

CLAMP METER36

COM V

600VTRUE RMS

DC / ACZEROA

DC

Model 36• AC/DC current

and voltage

• True-rms

• Max hold

POWER HARMONICSANALYZER41B®

Model 41B• Harmonics

and power

• Waveform,spectrum, textdisplay andstorage

• RS-232,FlukeView®

software

ScopeMeter® 123• Innovative,

easy-to-usefeatures

• Scope, meterand recorder inone handheldpackage

• Connect-and-View™ hands-off operation

Fluke. Keeping your worldup and running.

Fluke CorporationPO Box 9090, Everett, WA USA 98206

Fluke Europe B.V., PO Box 1186, 5602 BD,Eindhoven, The Netherlands

For more information call:U.S.A. (800) 443-5853 orFax (425) 356-5116Europe/M-East (31 40) 2 678 200 orFax (31 40) 2 678 222

T5 ElectricalTester• OpenJaw®

current info upto 100A ac

• Two models:600V and1000V CAT III

16 MULTIMETER

SELECTMAXMIN˚C / F

TEMPRANGE

AC / DCA

TEMPERATURE

V•Check

Model 16• Temperature

Canada (800) 36-FLUKE orFax (905) 890-6866Other countries (425) 356-5500 orFax (425) 356-5116Web access: http://www.fluke.com

©2000 Fluke Corporation. FlukeView is a registeredtrademark of Fluke Corporation. All rights reserved.Printed in U.S.A. 2/2000 1263690 A-ENG-N Rev E

Printed on recycled paper.

Model 43• Record sags and

swells

• Capture up to 40transientwaveforms

• Harmonics andpower

• 20 MHz scope

• RS-232, FlukeViewsoftware

43 POWER QUALITY ANALYZER

HOLDRUNPRINT

ENTERF1 F2 F3

RECORDMENU

SAVE

1 2

A mA COM V

TEMPERATURE

A

AutoHOLD

CANCEL

FAST MN MX

SETUP

MIN MAXHOLD REL

% msHz RANGE

dB

dB

ac+dc

ac+dc

ac+dc

ac+dc

F

nS

mA

mAA

mV

V

mV

V

OFF

C

A

A

A

TRUE RMS MULTIMETER89

A mA COM V

TEMPERATURE

A

CLEAR MEMVIEW MEM

LOGGING

SAVE

YES

NO

400mAFUSED

10A MAXFUSED

CAT 1000V

Fluke 89-IV•50,000-count

resolution withinstant readings

• 0.025% basic dcaccuracy

•100 kHc acbandwidth

• Internal memoryallows for stand-alone logging andstorage of up to1000 measurements

• Time-stampedMIN/MAX/AVG

•Temperature

ScopeMeter®190Series•200 MHz

bandwidth

•2.5 GS/s real timesampling

•27,500 pointsrecord length

•Advanced triggermodes

•Up to 1000Visolated inputs

• 4 hour battery life

• Built-in meter andrecorder

HHOLD

Hz RANGEONOFF

31TRUE RMS CLAMP METER

0 1 2 3 40 A

100ms

AUTO

RMSA

H

33TRUE RMS CLAMP METER

HHOLD

MINMAX Hz

SMOOTHCREST RANGE

ONOFF

0 1 2 3 40 A

RECORD MAXSMOOTH

AUTO

RMSA

H

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ABCs of Multimeter Safety