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lnstructionManual

PN: 481 400'9-00'l Printedin Chlna @20028&K PrecisionCorP

22820Savi Ranch ParkwaY YorbaLinda, CA 92887 USA T E L :( 7 1 4 )9 2 1 - 9 0 9 5 FAx. (714J921 6422 w.DKpreclslon com

1148 Analog Multimeter

SAFETY

1.

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An electrical shock causing 10 mA of current tc pass through the heart will strtpmost httnan lrcarlbeats. \/oltage as /ow as 35 volts dc or ac rms should be considereddangerotts and hazardotts sinceit can produca a lethal currcnt under ceftain conditions. Higher currents are even rnore dangerotts. Observe the following safety precautions: "SPECIFICANevorapply inputvoltagesltreaterthan those listedin the TIONS"section.Personalinjuryor damageto thc instrumentmay occLlr.

i n d r - r s t r ri ar sl e ;f o r e x a m p l e . 2 . T h i s m e t e ri s n o t r e c o m m e n d efdo r h i g hr r o l t a g e not for measurementsof 440 \1 AC or 600 \/ AC industrialpowe!.mains.The unit is intendedfor use with low energyoircttitsto /50 V AC or l0fl0 V DC or l i s u s eb y c o n n e c t i o n h i g he n e r g yc i r c u i t st o 2 5 0 V D C o r A C . A c c i d e n t am acrossa high voltage,high energypowersotlrcewhen lhe meteris set rrpfor mA measurementmay be very hazardous. 3.

Turn equipmentoff beforemakingrest connectionsin high voltagecircuits power. Dischargehlgh voltagecapacitorsaftg!"remDVinq

4.

t e a s u r e m e n ti sn h i g hv o l t a g ee q t l i p m e n t , W h e n m a k i n gv o l t a g eo r c u r r e n m nevertouchequipment,meter,or test leadsurhilepower is applied.

5.

b to i n qt e s t e da n d i h e f i t ht h e e q L r i p m e n l f p o s s i b l ef,a m i l i a r i zyeo t l r s e lw locationof its highvoltagepoints.Flowever.remenlborthal hiqh voliagemav d o i n t si n d e f e c t i v e q r l i p m e r ] l . a p p e a ra t u n e x p e c t e p

6.

B e c a r e f utl o a v o i dt o u c h i n ga h i q hv o l t a g ep o i n t .R e m e m b e trl l a ta c l i n ev o l f age mav be presentin equipmentundertest (for example,at on-nIfswitch' to an ac otitlet, fuses,lransformer.etc.).any time the eqllipmentis connercted even if it is turnedoff.

7.

When removingthe cover for servicingor batteryreplacernent,removetest leads and make sure that the inpLttis disconnectedfrom any high voltage.

8.

" o n e h a n di n l h e p o c k e t "t e c h n i q u ew h i l eh a n d l i n ga n U s e t h e t i m ep r o v e n instrumentprobe.Be particularlycarefulto avoid contactinga nearbymetal objectthat couldprovidea good groundreturnpath.

SPECIFICATIONS When using a probe,only touchthe insulatedponion.Nevertouch the exposedtip ponion. 1 0 , Use an insula.tedfloor materialor a large,insulatedfloor mat to stand on, and an insulatedwork surfaceon which to place equipment;make certainsuch surfacesare not damp or wet. 1 1 . When testingac poweredequipment,rememberthat ac line voltageis usually presenton some powerinputcircuitssuch as on-offswilches,fuses, power transformers,etc., any time the equipmentis connectedto an ac out-let.This is true even if the eouiomentis turnedoff.

12 Some equipmentwith a two-wireac power cord. includingsome with a polar-

ized power plug,is the "hot chassis"type. This includesmost recenttelevisionreceiversand audioequipment.A plasticor woodencabinetinsulates the chassisto protectthe customer.When the cabinetis removedfor servicing, a seriousshockhazardexistsif the chassisis touched.To make measurementsin "hot chassis'equipmenl.alwaysconnectan isolationtransformerbetweenthe ac outletand the equipmentundertest.The BK Precision ModelTR-11 0 or 1604 lsolationTransformer,or Model 1653or 1655AC PowerSupplyis suitablefor most applications. To be on the safe side,treat all two-wireac poweredequipmentas "hot chassis"unlessyou are sure it has an isolatedor eanh groundchassis.

1 3 On inslrumentsor any equipmentwith a three-wireac powerplug,only use a 3-wireoutlet.This is a safetyfeatureto keep the housingor other exposed elementsat eanh ground.

" C + 2 8" C Accuracyspecificationsapplyfrom + 1 8 t o DC VOLTS '120V' 0-300mV,3V, 12V'30 V' Ranges: 300v, 1200v 20,000ohmsPervolt SensitivitY: t 3oloof full scale AccuracY: AC VOLTS Ranges: SensitivitY: i Accuracy@50/60H2: (t1 dB) ResPonse: : FrequencY

bc cuRnelt j

, Ranges: ' Accuracy: BurdenVoltage

hrstsratce Ranges:

Neverwork alone.Someoneshouldbe nearbyto renderaid if necessary. Trainingin CPR (cardio-pulmonary resuscitation) first aid is highly recommended. AccuracY: MaximumOPenCircuitVoltage: MaximumShortCircuitCurrent:

0-12V,120V,300v, 1200v 9,000ohmsPervolt t 4% of fullscale 40 Hz to 100kHz 12 V range: 40 Hz to 10 kHz 120V range: 40 Hz to 5 kHz 300V range: 40 Hz to 1 kHz 1200V range: 0-50pA,3mA.30mA,300mA,12A t 3% of full scale Lessthan600 mV

RX1,0 to 2 kohms,mid scale20 ohms RXl0, 0 to 20 kohms,mid scale200ohms R X 1k,0 to 2 Mohms,midscale20 kohms R X 10k,0 to 20 Mohms,midscale200 kohms I 3% of full scale RXl,Xl0,Xlkranges:3V R X 10krange:9 V R X 1 rangei150mA : 5mA R X 1 0r a n g e 1 RXlkrange:150PA R X 10Krange:100UA

d B M E A S U R E M E N (Td B s c a l e ) - 1 0d B t o + 2 3 d B o n 1 2 V A C r a n g e Ranges. + 1 0d B t o 4 3 d B o n 1 2 0 V A Cr a n g e + 1 8d B t o 5 1 d B o n 3 0 0 V A C r a n g e + 3 0d B o n + 6 3 d B o n 1 2 0 0V A C r a n g e 1 mW across600 ohms 0 dB Reference: BATTERYTEST (good - bad scale) 1.5 V rangefor batterytesl only Range: 7.5 ohms Load: BatteryDrain: 200mA TRANSISTORLEAKAGE TEST (lceoscale) Ranges: 0 t o 1 5 0p A o n R X l k r a n g e 0 to 15 mA on R X 10range 0 to 150 mA on R X 1 range t 5% of scale arc Accuracy: MaximumAppliedVoltage: 3 V, voltagemeasuredon LV scale TRANSISTORGAIN MEASUREMENT 0 to 1,000measuredon hFEscalewilh Range: rangeswitchset to R X 10 t 3% of scale arc Accuracy: Test Leads : Special,supplied GENERALSPECIFICATIONS Movement: Jeweledpivots,50 pA full scale Scale Length: 3-112inches,mirroredscale +or-,polarityreversalswitch Polarity: Batteries:Two 1.5 V AA and one 9 V PowerSource: 250 volt ceramicfuse. Not for high energy OverloadProtection: powprmeasurementsabove250 volts. 0to+40"C OperatingTemperature: D i m e n s i o n(sH: x W x D ) . 5-314"x3-718"x 1-318"(147 x 99 x 35 mm) 11 oz. (308 g) with batteries Weight: AccessoriesSupplied: Batteries Test leads, 1 red and 1 black Transistortest leads lnstructionmanual. OptionalAccessories: Carryingcase, LC-298

CONTROLSand INDICATORS

Fig. 1 Controls and indlcators

Scale Mirror Helpseliminatemeasurementerrorscaused by parallaxwhen viewingscale

OPERATINGINSTRUGTIONS A

Q Scale Measurementscalefor resistancereadings. DCV,A&ACVScale Measurementscalefor DC volts,DC amperesand AC volts . BATT. 1.5V Scale Scale for measuringcondition(good/?/bad)of 1.5 volt batteries. 5.

Be sureto read thoroughtyunderslandand followthe practics givenin the SAFEW sectionol thismanualto reducethe riskof electricalshock. TIPS GENERALCAREand OPERATING saction see the MAINTENANCE are in goodcondition; Makosurebatteries of this manualfor batteryreplacementinstructions

hrr Scale Scale for measuringtransistorgain.

Alwaysviewthe meterpointerso that its reflectionin the scalo minor ls parallaxerrors directlybehindit. Thiseliminates

l c e oL , V and Ll Scale Measurementscale for transistorleakage.

Whenthe meterleadsare ramovod,the pointershouldbe al exactzero lf needed.adjustthe pointerto readzeroby tappingthe meterfacegentlywhlle zeroscrew. tha mechanical adjusting

dB Scale Measurementscale for decibels(dB). Function/RangeSelector Rotary switch to select measurementrange and function. v.

Awnnltuc

DC+, DC- (Polarity)Switch Polarityselectorfor DC voltageand current.

The greatestaccuracyis achievedwhenreadingsare in the upperpartof the melerscale.As a generalrule,selectthe nextlowerrangewhenrsadlngs are lessthanhalfscale. set the Functlon/Rangeswltchto yourmeasurements, Aftercompleting ACV and removeleadsfromthe meter.Neverleavethe Functlon/Range switchin the Q Dositionto conservebatterypower.

1 0 .0Q .ADJust Zero ohms adjust beforetaking resistancemeasuremenls(leads shorted). 1 1 . C O MJ a c k Inputfor black, negativepolarity(common or reference)test lead. 12. VQmAJack Inputfor red, positivepolarity,test lead for most measurementsexcept 12 A range. 1 3 . D C 1 2 AJ a c k Red, positivepolaritytest lead input for current measurementsup to 12 A. 14. Meter Zero Mechanicaladjustmentto set pointerof meter to exact zero positionwhen power is off. 6

DC VOLTAGEMEASUREMENTS

N tout'o* Nevdr try to measure voltages greater than 120o v. Higher voltages could damage the meter and/or increase the risk of electical shock To prevent instrument damage. always set the Function/Range selector to a rango highor than the maximum voltage you expect to measure. ff the voltage is unknown. staft with the highest range' jack 1 Plug black test lead into the COM jack and red test lead into the VQmA Set Polarity selector to DC+ or DC - as determined by polarity of voltago vou intend to measure.

RESISTANCE MEASUREMENTS 3 Set Function/Range switch to desired V: select1200V.

range. lf range is unknown,

CAUTION 4. Connect black test lead to point of reference (common), red test lead to desired measuring point. The common should never exceed 600 V (DC + AC peak) with respect to earth ground. 5. Read voltage at related scale. For best accuracy, try to get a reading of al least 1/3 scale deflection.

Never apply a voltage to the input terminals when the reslslance function is selected to avoid damage to the meter. Before taking a resisfance measurement, make sure circuit under test is elect"cold", power rically off and any capacitors discharged.

*

Plug black test lead into the COM jack and red test lead into the VOmA jack, )

1 Sel FunctionlRangeswitch to desired ohms/resistancerange.

AC VOLTAGE MEASUREMENTS 3.

Shonleads together firmly and verify that pointer rests on exact zelo ohms lf needed, adjust the 0c, ADJ control to assure poinler rests on zero Repeal this check each time range is changed. lf pointer cannot be zeroed, one or both batteries may be weak See the MAINTENANCE section of this manual to check and/or replace the batteries.

4.

Connect test leads across component or circuit being measured. Obtain correct resistancevalue by multiplyingscale reading by X lactor (X1/X1o/etc) of range selected For besl accuracy, select a range that gives a reading as close as possible to the zero end of the scale.

CAUTION Never try to measure voltages greater than 12OOV. Higher voltages could damage the meter and/or increase the risk of electrical shock. To prevent instrument damage, always set the Function/Range selector to a range higher than the maximum voltage you expect to measure. lf the voltage is unknown, staft with the highest range. 1. Plug black test lead into the COM iack and red test lead into the VCImA jack.

NOTE Whenmakingresistance be awarethatthe open measurements, circuitvoltagebetweenthe COM and + terminalsis highenough to foruard-bias Thisvoltageis about3V in typicalsemiconductors. t h eX 1 ,X 1 0 , X l K r a n g e sa n da b o u tI V i n t h eX 1 0 Kr a n g e .

,

2. Set Function/Range switch to desired V- range. lf range is unkndwn, select1200 V. 3. Connect black test lead to point of reference (common), red test lead to desired measuring point. The common should never exceed 600 V (DC + RC peak) with respect to earth ground.

DIODETESTS I OUT-OF-CIRGUIT i||

I i

4. Read voltage at related scale. For best results, try to get a reading of at least 1/3 scale deflection.

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I

fh" resistance function of this meter can be used to check the forward/reverse " " resistance ratio of diode devices. This is not a fool-proof test, but it's reasonabty reliable in most cases Also, see Transistor Tests for more semiconductor checks. 'l

.

2.

Remove diode or similar device beinq tested from circuit. Select desired resistance range, typically Xl K.

3. Connecttestleadsacrossdiode,thenreverseconnections Resistance ratio shorrldbe at least10,000:1. nearinfinl$in one directionand low resistance in otherdirection. . lf meterreadingis nearinfinitvin bothdirections, the diodedeviceis probablyopen. . lf meterreadingis verylow in bothdirections, the diodedevicois probably shorted

Bad / good Judgment . Transislorbad,open:Zero(0) readingin bothstates,with baseopenor closed. . Transistor bad,collector-to-emitter short:Highreadingin bothstales,withbase oDenor closed. Note Germanium Transistors Note:The leakagecurrentin thesetranslstors alwaysflows lo the collector. Thiscausesan errorin the amplification factorreading.To compensate forthiserror,subtractthe readingon the ICEOscalefromthe reading on the hFE scale.

TRANSISTOR MEASUREMENTS Thismeterprovidosthreetransistor measurement: leakage.amplification factorand had/good condition. Thesemeasurements are madewiththe useof transistor test socl