Fluke 8050A User manual

PIN 530907
October 1979
Rev 27/84
©1984, John Fluke Mfg, Co" Inc, All rights reserved, Litho in U,S.A.
8050A
Digital
Multimeter
Instruction Manual

WARRANTY
Notwithstanding any provision of any agreement the following warranty is exclusive:
The JOHN FLUKE MFG. CO., INC., warrants each instrument it manufactures to
be free from defects in material and
workmanship undernormal use and service
for theperiod of 1-yearfrom date of purchase. This warrantyextends only
totheoriginal purchaser. This warranty shall not apply to fuses, disposable batteries (rechargeable typebatteries are
warranted
for 9O-days), or any product or parts which have been subject to misuse, neglect, accident, or abnormal
conditions
of operations.
In the event of failure of aproduct covered by this warranty, John Fluke Mfg. Co., Inc., will repair and calibrate an
instrument returned to an authorized Service Facility within 1year of the original purchase; provided the warrantor's
examination discloses
to its satisfaction that the product was defective. Thewarrantor may, at its optioh, replace the
product in lieu
of repair. With regard to a.ny instrument returned within 1year of the original purchase, said repairs or
replacement will be made without charge. If the failure has been caused by misuse, neglect, accident, or abnormal
conditions
of operations, repairs will be billed at anominal cost. In such case, an estimate will be submitted before
work is started, if requested.
THE FOREGOING WARRANTY
IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING
BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS,
OR ADEQUACY FOR ANY PARTICULAR PURPOSE OR USE. JOHN FLUKE MFG CO., INC., SHALL
NOT BE LIABLE FOR ANY SPECIAL,INCIDENTAL,
OR CONSEQUENTIAL DAMAGES, WHETHER IN
CONTRACT, TORT,
OR OTHERWISE.
If any 'allure occurs, the following steps should be taken:
1. Notify the JOHN FLUKE MFG. CO., INC., or nearest Service facility, giving full details of the difficulty, and
include the model number, type number, and serial number. On receipt
of this information, service data, or
shipping instructions will be forwarded to you.
2. On receipt of the shipping instructions, forward the instrument, transportation prepaid. Repairs will be
made at the Service Facility and the instrument returned, transportation prepaid.
SHIPPING TO MANUFACTURER FOR REPAIR OR ADJUSTMENT
All shipments of JOHN FLUKE MFG. CO., INC., instruments should be made via United Parcel Service or"Best Way'"
prepaid. The instrument should be shipped in the original packing carton; or if it is not available, use any suitable
container thatis rigidand
of adequatesize. If asubstitutecontainer is used.the instrument shouldbewrapped in paper
and surrounded with at least four inches of excelsior
or similar shock-absorbing material.
CLAIM FOR DAMAGE IN SHIPMENT TO ORIGINAL PURCHASER
The instrument shoula be thoroughly inspected immediately upon original delivery to purchaser. All material in the
containershould bechecked against theenclosed packing list. Themanufacturerwill notbe responsible forshortages
against the packing sheet unless notified immediately. Ifthe instrument is damaged in any way, aclaim should be filed
with the carrier immediately. (To obtain aquotation
to repair shipment damage, contact the nearest FlukeTechnical
Center.) Final claim and negotiations with the carrier must be completed by the customer.
The JOHN FLUKE MFG. CO., INC, will
be happy to answer all applications or use questions, which willenhanceyour
use
of this instrument. Please address your requests or correspondence to: JOHN FLUKE MFG. CO .. INC .. P.O. BOX
C9090, EVERETT, WASHINGTON 98206, ATTN: Sales Dept. ForEuropeanCustomers: Fluke (Holland) BV., P.O. Box
5053, 5004 EB, Tilburg, The Netherlands.
'For European customers, Air Freight prepaid.
John Fluke Mfg. Co., Inc., P.O. Box C9090, Everett, Washington 98206
Rev. 6/81

SECTION TITLE
Table of Contents
PAGE
1INTRODUCTION AND SPECiFiCATIONS 1-1
I-I. INTRODUCTION 1-1
1-4. OPTIONS AND ACCESSORIES 1-1
1-5. SPECIFICATIONS 1-1
2OPERATION 2-1
2-1. INTRODUCTION .............•.............................. 2-1
2-3. SETTING UP YOUR INSTRUMENT 2-1
2-4. Unpacking ..............................•.................. 2-1
2-8. AC Line Voltage Requirements 2-1
2-10. Fuse Replacement ....•............••.....•........•.....•... 2-1
2-13. FRONT PANEL FEATURES 2-2
2-15. Display ...........................•...•..........•......... 2-2
2-18. SIGNAL INPUT LIMITS .......•....................•..•..... 2-2
2-20. OPERATING TECHNIQUES 2-3
2-22. ACj DC Voltage (V) .......•................................. 2-3
2-24. ACjDC Current (mA) ..............•........................ 2-3
2-26. Resistance (0) 2-7
2-28. Conductance (S = 10) 2-7
2-30. Diode Test 2-7
2-32. Relative (RELATIVE) 2-7
2-36. Decibel (dB) ..............•................................. 2-11
2-38. INITIAL CHECKOUT PROCEDURE 2-12
2-41. APPLICATIONS 2-12
2-43. DC Voltage Measurement 2-12
2-51. Current Measurement ...................•................•.. 2-13
2-56. Resistance Measurement 2-13
2-62. Conductance Measurement 2-14
2-80. Relative Measurement ..........................•..•......... 2-16
2-84. AC Voltage and Current Measurement 2-16
3THEORY OF OPERATION 3-1
3-1. INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-1
3-3. FUNCTIONAL DESCRIPTION .•........................•.... 3-1
3-5. CIRCUIT DESCRIPTION 3-1
(continued on page ii)

TABLE OF CONTENTS, continued
SECTION TITLE PAGE
3-7. AID Converter ..........................................•.. 3-1
3-18. Microcomputer 3-2
3-20. Signal Conditioning 3.{j
3-31. True-RMS Converter 3-8
3-38. Touch-Hold Circuit 3-8
3-40. Voltage Protection .................•...................•.... 3-8
3-43. Current Protection ..................................•....... 3-8
4 MAINTENANCE. .. . .. .. ... ... ... .. . .. ... . .. .. .... . . .. . .... .. . . .. . .. 4·1
4-1. INTRODUCTION 4-1
4-4. SERVICE INFORMATION 4-1
4-7. GENERAL INFORMATION 4-1
4-9. Interior Access •................. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-1
4-24. dB Reference Impedance Power-UpSetting .. ................. .. 44
4-26. Cleaning 4-5
4-28. PERFORMANCE TESTS ....................................• 4-5
4-30. Initial Procedures ..................••....................... 4-5
4-32. Display Test ..................................•..........•.. 4-5
4-34. Linear Voltage Test .......•.......................•......... 4-6
4-36. dB Voltage Test ..........................•.........•........ 4-6
4-38. Current Test 4-7
4-40. Resistance and Conductance Tests .....................•....•.. 4-7
442. CALIBRATION ADJUSTMENTS ........•...................• 4-8
444. DC Calibration ........................................•.... 4-8
4-46. AC Calibration 4-8
4-48. Jumper Selection 4-8
4-57. TROUBLESHOOTING .....•......•... " 4-12
5LIST OF REPLACEABLE PARTS 5-1
TABLE OF CONTENTS ......................•......•..•....• 5-1
5-1. INTRODUCTION ............•.•............................. 5-2
5-3. PARTS ORDERING INFORMATION 5-2
6OPTIONS AND ACCESSORIES 6·1
TABLE OF CONTENTS ...........................•......•... 6-1
INTRODUCTION .....................................••..... 6-2
ACCESSORIES ....•......................................... 600-1
OPTIONS ........................................•.......... 601-1
7SCHEMATIC DIAGRAMS 7·1
TABLE OF CONTENTS .........................•........•... 7-1
APPENDIX A A·1
ii

TABLE
1-1.
1-2.
2-1.
2-2.
3-1.
4-1.
4-2.
4-3.
4-4.
4-5.
4-6.
4-7.
4-8.
4-9.
4-10.
4-11.
4-12.
4-13.
List of Tables
TITLE PAGE
80S0A Accessories .....•.....•.......................•.•........•.. 1-2
8050A Specifications ..••.............••........•...............••.. 1-2
8050A Controls, Indicators, and Connectors ....•..............•....... 2-3
Maximum Input Signal Limits 2-5
AC Buffer Gains .•....................•....•••.......•.•.•......... 3-8
Required Test Equipment ...•.•........•...•....•................•.. 4-2
dB Impedance Selection •..........•........••............••.•....•. 4-4
Display Test •.... . . . . •. . . . . . . . •. . . . . . •. . . . •. . . . . . . . . . . . . . . . •. . . •. . 4-5
Linear Voltage Test ..................•..........•..........•..••... 4-6
dB Voltage Test •..........•.•...................................•. 4-7
Current Test ••••......••...••...........•••••........•.........•.. 4-7
Resistance and Conductance Tests 4-8
DC Calibration ........•.•..................•...................... 4-10
AC Calibration
................•..............•...............•.... 4-10
US Jumper Positions ••.......•.......................•.••••.......• 4-11
U33 Jumper Positions ...•.••••.......••...•..•......•.••..•......•• 4-12
Test Points
.....•...............•...................•.•...•...•...• 4-13
Troubleshooting Guide ............••..........•.....•.............. 4-14
iiil iv

FIGURE TITLE
List of Figures
PAGE
Frontispiece
I-I.
2-1.
2-2.
2-3.
2-4.
2-5.
2-6.
2-7.
2-8.
2-9.
2-10.
2-11.
2-12.
2-13.
2-14.
2-15.
2-16.
2-17.
3-1.
3-2.
3-3.
3-4.
3-5.
3-6.
4-1.
4-2.
8050A Digital Multimeter ....................................•......
8050A Dimensions ......•..........................................
Controls, Indicators, and Connectors .•...............•...............
Liquid Crystal Display " ....•................•.........
AC/DC Voltage Operation ....•....•................•...............
AC/DC Current Operation .............•...•.................•......
Resistance Operation ........................................•......
Conductance Operation .................................•...•••.....
Diode Test Operation ...•...................................•......
Relative Operation ..........................................•......
dB Voltage Operation ........•....................•................
Circuit Loading Error ........................•.....•.............••
Calculating Burden Voltage Error .................•.............•....
Transistor Beta Test Fixture .........•.............................•.
dB Circuit Gain or Loss Measurements ...•......•.............•.•....
Waveform Comparisons ...•...........••....................•.•....
Crest Factor ...........••..............••...........•....•........
Total RMS Value .......................•......................•...
Measuring Amplifier Bandwidth ••..................•................
8050A Functional Block Diagram ...................•................
AID Converter ...............•...•.•..................•...........
AID Converter Waveforms ......................................•.•
Microcomputer Simplified Block Diagram •...........................
Signal Conditioning ............................•..................•
RMS Converter ...........................................•......•
Display PCB Access .
Calibration Adjustment Locations .
v
VI
1-6
2-2
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-13
2-14
2-15
2-17
2-18
2-19
2-19
2-20
3-3
3-4
3-5
3-6
3-7
3-9
4-3
4-9

80SOA Dlglta, MU'"meter
vi

Section 1
Introduction and Specifications
1-1. INTRODUCTION
1-2. Your JohnFluke Model8050A isa portablebench-
type digital multimeter (DMM) with a
4-1 /2 digit liquid
crystal display (LCD). The
8050A has all the following
industry-standard features:
•Voltage measurements from
10 p.V to looOV dcand
10 mV to 750V true-rms ac.
•
•
•
Automatic polarity indication and overrange
indication.
Protection from overloads and protection from
transients
of up to 6kV, 10 microseconds.
Dual-slope integration a/dconversion to ensure
noise-free measurements.
•Currentmeasurements from
10 nA to 2A dc and 10
p.A to 2A true-rms ac.
•Resistance measurements from
10 mO to 20MO.
The
8050A also has severalspecial measurementfeatures.
These special features include the following:
•Long term calibration stability
(l year).
1-3. The 8050A is warranted for aperiod of one year
upon shipment
of the instrument to the original
purchaser. Conditions
of the warranty are given at the
front ofthis manual. The8050A
is typicallypowered from
ac line voltages but may be powered by the optional
rechargeable battery.
•
•
•
•
Conductance measurements up to 100,000 MO.
Voltage measurements in decibels, that can be
referenced to I
of 16 user selected reference
impedances.
Resistance ranges that supply enough voltage to
turn on a
PN junction to allow diodes and
transistors to be tested.
The ability to store any input signal as an offset or
relative reference value.
1-4. OPTIONS and ACCESSORIES
1-5. The use of the 8050A can be enhanced by the
accessories available for this instrument. The accessories
are listed in Table
1-1. This instrument can be ordered
with the
Option 8050A-O I Rechargeable Battery.
Detailed information on options
and accessories is
contained in Section 6of this manuaL
1-6. SPECIFICATIONS
1-7. Specifications for the 8050A are listed inTable 1-2.
Specifications for the Option 8050A-Ql Rechargeable
Battery and other accessory specifications are given in
Section 6of this manual.

INTRODUCTION
SPECIFICATIONS
Table 1·1. 8050A Accessories
MODEL DESCRIPTION MODEL DESCRIPTION
C86
Ruggedized Carrying Case 80J-10 Current Shunt
Y8205
Soft Carrying Case
8OK-6
High Voltage Probe
MOO-20Q.611 Offset Mounting Kit 80K·40 High Voltage Probe
MOQ.20Q.612
Center Mounting Kit 83-RF
RF Probe
MOQ.200-613
Dual Mounting Kit 85-RF
RF Probe
8OT-H
Touch-Hold Probe Y8100 DCIAC Current Probe
8OT-150C
Temperature Probe. Celsius
Y8101
AC Current Transformer
8OT-150F
Temperature Probe. Fahrenheit
Y8134
Deluxe Test Lead Set (safety designed)
801-600
Current Transformer
Y8140
Slim-Flex Test Leads
Table 1·2.
8OSOA Specifications
ELECTRICAL The electrical specifications given apply for
an operating tem-
perature
of 18"C to 28°C (64.4° Fto 82.4" F), relative humidityupto
90%. and a1-year calibration cycle.
Functions
.................•.............. DC volts, AC volts (linear and dB), DC current. AC current.
resistance, diode test, conductance. relative.
DC Voltage
RANGE RESOLUTION ACCURACY for l·Year
±200 mV
10 flV
±2V 100
flY
±20V 1mV ±(0.03%
of reading +2 digits).
±200V
10mV
±1000V 100 mV
INPUT IMPEDANCE 10 Mel in parallel with <100
pF. all ranges.
NORMAL MODE REJECTION RATIO
... >60 dB at 60 Hz or 50 Hz.
COMMON MODE REJECTION RATIO... >90 dB at de. 50 Hz or 60 Hz (1 kO unbalanced)
(>120 dB available on request)
COMMON MODE VOLTAGE (MAXIMUM)
500V dc or peak ac
RESPONSE TIME TO
RATED ACCURACY 1second maximum
MAXIMUM INPUT
..................•.•. 1000V de or peak ac continuous (less than 10 seconds duration on
both the
200 mV and 2V ranges).
*DC voltages can also be measured using the dB mode with .01 dB resolution between 5% of range and full range.
1-2

INTRODUCTION
SPECIFICATIONS
Table 1-2. 8OSOA Specifications (cont)
AC Volts (True RMS Responding, AC Coupled)
VOLTAGE READOUT ACCURACY
±(% of reading +number of digits), between 5% of range and full
range.
iNPUT RESOLUTION RANGE 20
Hz**
45Hz
1kHz 10 kHz 20 kHz 50 kHz
VOLTAGE
10
mV· 200 mV 10/N
200mV
I
I
0.lV-2V lOOl-tV 2V
1%+10
.5%+10 1%+10 5%+30
1V·20V
1mV 20V I
10V 200V
10mV
200V !
100V-750V
loomV
750V
**Tvpicallv 3 to 5digits of rattle will be observed at full scale at 20 Hz.
RESOLUTION .....................•..•. 0.01 dB from 5% of scale to full scale; 0.1 dB from 1-5% of scale, 1dB
below
1% of scale
VOLT -Hz PRODUCT
EXTENDED dB SENSITIVITY
107max (2ooV max @ 50 kHz)
Typically -72 dB (6000 Ref) ±1 dB
to 10 kHz
EXTENDED FREQUENCY RESPONSE
.. Typically -3 dB at 200 kHz
COMMON MODE REJECTION
RATiO
(1 kO unbalance)
CREST FACTOR RANGE
:>60 dB at 50 Hz or 60 Hz
Waveforms with aPeaklRMS ratio
of 1:1 to 3:1 at full scale,
increasing down range
INPUT
IMPEDANCE.................... 10 MO in parallel with <100 pF
MAXIMUM INPUT VOLTAGE 750V rms or 1000V peak continuous (less than 10seconds duration
on both the 200
mV and 2V ranges), not to exceed the volt-hertz
product
of 10
7
RESPONSE TIME .. . . ... . .. . . .. . . .. .••. 2seconds maximum within arange
REFERENCE IMPEDANCES
..•...•. .•.. Sixteen user-selectable impedance reference levels are provided to
reference a 0 dBm, 1mW level (500, 750, 930, 1100, 1250, 1350,
1500,2500,3000,5000,6000,8000,9000.10000,12000). and an
80 impedance reference level is provided to reference a0dBWlevel.
NOTE:
On request, the NOT SPECIFIED portion of the lOOV-750V Range can be extended
to the Volt·Hertz product of 10:
dB Ranges
INPUT
VOLTAGE dBm
(600 nREF) ACCURACY: from
5% of range to full scale, l-year
RANGE
20Hz 45Hz 1kHz 10kHz 20kHz
50kHz
0.77 mV· 2mV -60 to -52
200 mV*
0.5 dBm
2mV
2V
-52 to +8 200
mV*
0.1V-2V -18 to +8 2V ±o.25dBm ±0.15 dBm ±o.25dBm
lV·20V +2to +28 20V ,
10V-200V
+22 to +48 200V I
100V 750V +42 to +60 750V
*When 200 m V range is selected the B050A autoranges for bestaccuracy for 2V inputs and less.
1-3

IN'rRODUCTION
SPECIFICATIONS Table 1-2. 8050A Specifications
(cont)
DC Current
RANGE RESOLUTION ACCURACY
for l·Year BURDEN VOLTAGE
200;.tA 0.01
JJ.A
2mA
0.1 JJ.A
±(O.3% of reading + 2 digits 0.3V max
20mA
1 JJ.A
200mA
tOJ,lA
2000mA
l00J,lA I0.9V
max
OVERLOAD PROTECTION (ac/de) 2A1250V fuse in series with 3A/600V fuse (for high energysources)
AC Current (True RMS Responding, AC Coupled)
INPUT RANGE 20 Hz"* 2
kHz 10 kHz 20 kHz
BURDEN
CURRENT RESOLUTION 45
Hz
VOLTAGE
10
J.LA •200 JJ.A 0.01 JJ.A
200JJ.A
I
I
100j.lA·2mA 0.1 JJ.A 2mA
I
1
mA ·20mA lilA 20mA 2%+10
1%+10 2%+10 0.3V rms max
I
10mA·200mA 10JJ.A 200mA
100 mA· 2000 mA
100J.LA
2000mA
0.9V rms max
UTvpicallv 3to 5digits of rattle will be observed at full scale at 20 Hz.
CREST FACTOR RANGE Waveforms with aPeak/RMS ratio of 1:1 to 3:1 at full scale
Resistance
RANGE RESOLUTION ACCURACY
for l·Year
FULL SCALE VOLTAGE ACROSS
UNKNOWN RESISTANCE
200n O.Oln
.19V
2kQ O.1Q ±(O.l% reading + 2 digits +
.02m
1.2V
20kO m.2V
200
kO
100
±(.O5% of reading +2digits)
2V
2000 kQ
lOOn .2V
20Mn 1 kO
±(O.25% reading +3digits)
2V
OVERLOAD PROTECTION ...........•. 500V dc/ae rms on all ranges
1-4
OPEN CIRCUIT VOLTAGE
..
RESPONSE TIME ..•••......•...•......
(TO RATED ACCURACY)
DIODE TEST
-J+
Less than 3.5V on all ranges
10 seconds maximum on 20 MO range; 2seconds maximum on all
other ranges
Thesethree ranges have enough voltage
to turn onsiliconjunctions
to check for proper forward-to-back resistance. The 2kO range is
preferred and is marked with alarger diode symbol
on the front
panel of theinstrument. The threenon-diodetestrangeswill not turn
on silicon junctions so in-eircuit resistahce measurements can be
made with these three ranges

INTRODUCTION
SPECIFICATIONS
Table 1·2. 8050A Specifications (cont)
Conductance
RANGE RESOLUTION ACCURACY for l·Year
2mS
.1 IJ,S (10 Mnl
±(0.1% of reading +5digits)
200
nS
.01 nS
:!:(0.5% of reading +20 digits)
(100000
Mnl
MAXIMUM OPEN CIRCUIT VOLTAGE .. <3.5V
OVERLOAD PROTECTION
.•.....•..•.. 500V dc/ac rms on all ranges
CONDUCTANCE UNITS
..........••.••. We usethe international unit of conductance, thesiemen S= 1/0.
Another unit of conductance is the mho
Relative
RELATIVE REFERENCE An inputapplied when the RELATIVE button is depressed
to theON
position is held
as "0" referencepoint.Subsequentreadingsindicate
the deviation
(±) from this point. (Note: REL annunciator indicates
when this mode is enabled)
RELATIVE ACCURACY
..•...........••. Errorwill notexceed thesum of theerrors of the twomeasurements
ENVIRONMENTAL
Temperature Coefficient <0.1 times the applicable accuracy specification per°C for
0° Cto
18°C and 28°C to 50°C (32°F
to 64.4°F and 82.4°F to 122°F)
Operating Temperature
.••.••.•......•.••• DoC to 50°C (32°F to 122°F)
Storage Temperature
••..•..••......•..•.. (without batteries): -40°C to +70°C (-40°F to +158°F)
(with batteries): -40°C to
+50°C (-40°F to +122° F)
Relative Humidity......................... Up to 90%, O°C to 35°C (32-95°F), up to 70%, 35°C to 50°C (95-
122°
F), except on 2000 kO, 20 MO, and 200 nS ranges where it is up
to 80%, O°C to 35°C (32-95°F)
GENERAL
Maximum Common Mode Voltage
....••.•• 500V dc, orpeakae(lowterminalpotentialwith respect to powerIine
ground
Size.... 22 cm x6 em x 25 cm (8% in x2% x10 in) see Figure 1-1
Weight 1.08 kg (2 Ib 6oz)
Power Requirements (Line Only Models)
LINE
VOLTAGE................... ..... 90 to nov ac 47 to 440 Hz
105 to 132V ac, 47 to 440 Hz
200 to
264V ae, 47 to 440 Hz
Factory configured for customer specified voltage
POWER CONSUMPTION •••. .•.. ... .... 4W max
Standards I
EC 348 Protection Class 1
1-5

INTRODUCTION
SPECIFICATIONS
1-6
r---'0.65 in. (27,05 em)
r--9.90 in. 125,15 eml---
2.52 in. (6,40 em)
I
Figure 1-1. 8050A Dimensions

2-1. INTRODUCTION
2-2. This section describes how to set up and make
measurements with your 8050A. Even though you may
have used amultimeter before,
we recommend that you
read the entire section carefullyso that you can use all of
the 8050A features.
2-3. SETTING UP YOUR INSTRUMENT
2-4. Unpacking
2-5. This instrument is shipped in aspecial protective
container that should prevent damage to the
S050A
during shipping. Check the shipping order against the
contents ofthe containerand report any damage orshort
shipment to the place of purchase or the nearest Fluke
Technical Service Center. Alist
of these service centers is
located in Section 5. The container should include the
following:
Section 2
Operation
be used as aprop-stand or positioned out ofthe way. To
position the handle, pull outward on the hubs
of the
bandle and rotate the handle into position.
2-8. AC Line Voltage Requirements
2-9. AC line voltage requirements for your 8050A are
listed on adecalattached
to thebottom of theinstrument.
Refer to Section 4for the procedure to change the ac line
voltage setting.
CAUTION
Do not connect the power cable to the
Instrument before verifying that the Intended
source matches the ac line configuration of
the Instrument.
•
•
•
The S050A Multimeter
Two test leads (one red and one black)
Line power cord
2-10. Fuse Replacement
2-11. There is one, user replaceable, fuse in the 8050A.
The fuse,
Fl, and the fuse holder form an integral part of
the
rnA input connector and can be removed without
special tools. The fuse rating
is: 2A, normal blow
(recommended part AGX2).
•The 8050A Instruction Manual
2-6. If reshipment of the instrument is necessary, please
use
the original shipping container. If the original
container is
not available, be sure that adequate
protection is provided to prevent damage during
shipment. We recommend
that the instrument be
surrounded by
at least three inches of shock-absorbing
material
on all sides of the container.
2-7. Remove the 8050A from the containerand place it
in aconvenient location.
To facilitate operation in
different locations, the carrying handle on the meter can
2-12. Use the following procedure to replace the fuse,
Fl:
1. Set the POWER switch to OFF.
2. Remove the input power cord from the SOSOA.
WARNING
DO
NOT ATTEMPT TO REPLACE THE FUSE
WITH THE INSTRUMENT TURNED ON OR
CONNECTED
TO LINE POWER.
2-1

OPERATION
FRONT PANEL FEATURES
3. Refer to Figure 2-1, item 5for the location of
the fuse holder. The fuse holder is an integral
part of the rnA input connector.
4. Using acoin or wide blade screwdriver, pushin
while turningthe fuse holder in the direction
of
the arrow on the front panel decal.
5. Pull out the fuse holder and replace the
defective fuse.
2·13. FRONT PANEL FEATURES
2-14. Before using your multimeter, take a few minutes
to become familiar with the use of the controls,
indicators, and connectors
of the8050A. The front panel
features are shown in Figure
2-1 and described inTable 2-
1. The features of the Liquid Crystal Display (LCD) are
also described in the following paragraph.
2·15. Display
2-16. Thefeatures of the Liquid Crystal Display(LCD)
are shown in detail in Figure
2-2. The position of the
floating decimal point
is determined bytherangeselected
(for linear measurements). The maximum measurement
value that can be displayed is one count less than the
range selected (e.g., maximum measured voltage
that can
be displayed in the 200 mV range would be 199.99 mY).
2-17.
To extend the life of the LCD and to ensure that
the display will be ready
to operate, observethefollowing
precautions:
•Do
not store or use the instrument in temperatures
above
or below those specified in Section 1.
•Do not store or use the instrument in humidity
above that specified in Section I.
NOTE
Low temperatures (within the specified
operating limits) willcause the LCD response
to be sluggish.
•Avoid prolonged exposure of the LCD to direct
sunlight (ultraviolet).
2·18. SIGNAL INPUT LIMITS
CAUTION
Exceeding the maximum signal Input limits
can damage the Instrument
RELATIVE
ON
.-.
J\
riM
ltll1S """"
__ AC
.. DC
D
Off
..
POWER
D~
OFF
....
8 9
Figure 2-1. Controls, Indicators, and Connectors
2-2

OPERATION
OPERATING TECHNIQUES
Table 2-1. 8050A Controls, Indicators, and Connectors
ITEM NO. NAME FUNCTION
1Display
4Y2-digit LCD display. Used to indicate measured input values and
an overrange condition. Also containsannunciators forhighvoltage.
decibel-display, and relative measurement functions.
2AC/DC Function Atwo-position switch (push IN and push OUT) used to select ac
Switch (IN)
or de (OUT) for current or voltage measurements.
3V
ImAikO/dB/S
Interlocked switches, used with the AC/DC Function switch toselect
Function Switches the measurement functions. Pushing one switch will release the
others. The decibel-display function
is selected by pushing the V
and
rnA switches simultaneously. The conductance function is
selected by pushing the
kO switch and one of two pairs of Range
Function switches.
4Range Switches Interlocked switches that select the measurement ranges. Pushing
aswitch selects the corresponding range and releases adepressed
switch(es).
5rnA Input Connector Afuse protected input connector for current measurements.
Fuse
is accessible from the front panel.
6COMMON Input Test lead connectorused as theloworcommon inputforall measure-
Connector ment functions.
7
VlkO/S Input Test lead connector used
as the high input for all voltage, resistance.
Connector continuity, conductance and decibel measurement functions.
aRELATIVE Function Push-on/push-off switch. Used to select the relative function for
Switch all measurements.
9
POWER Switch Push-on/push-off switch. Used for energizing and de-energizing
the instrument.
2-19. Before using the8050A, it is importantto notethe
maximum input limits that may be applied
to the
instrument. Table
2-2 lists the maximum signal input
levels allowed for each function, range, and input
connector.
WARNING
TO AVOID ELECTRICAL SHOCK, DO NOT
CONNECT THE COMMON INPUT CON·
NECTOR TO ANY SOURCE MORE THAN
500V DC, OR 500V AC RMS ABOVE EARTH
GROUND.
2·20. OPERATING TECHNIQUES
2-21. The following paragraphsdescribe how tooperate
the
8050A in each of its seven primary measurement
functions. Refer to the Applications paragraphs for
additional measurement techniques.
2·22. AC/DC Voltage (V)
2-23. Figure 2-3 describes how to operate the8050A for
ac or dc voltage measurements.
For all measurements,
select the highest range that
will provide the required
resolution
of the measurement. If measuringanunknown
voltage, set the DMM on the highest range, then
(if
needed) select alower range.
2·24. ACIDC Current (rnA)
2-25. Figure 2-4 describes how to operate the 8050A for
ac or dc current measurements. Turn off power to the
circuit being measured before breaking the circuit and
connecting the 80S0Ainserieswiththecurrentsource. To
minimizecommon modevoltages, breakthecircuitonthe
ground side
of the current source. The rnA input
connector contains an in-line fuse.
If the DMM does not
respond when measuringcurrent, check the
fuse (refer to
the fuse replacement procedure in this section). If
measuring an unknown current, set the DMM on the
highest range, then
(if needed) select alower range.
2-3

~r:==~\)------ ~_ =-_ ~_~ _------=::::-----...,/
~Bl~ 9
u9
D
Q=O 9udBJ" HIGH VOLTAGE
iD '91 HV-H
1
+---+-- (>40 Vdc or ac rms)
/1(' a=a= ad) a= REt " ~ BEING MEASURED
/I..--- -----J"
8050A DISPLAY ANNUNCIATORS
OPERATION
LCD DISPLAY
8050A-01 ONLY
LOW BATIERY INDICATOR
POLARITY SIGN
DISABLED DURING
Vac, mA AND
kO FUNCTIONS
-----,
r;;.-----<
:J D
L-------1
8050A OVERRANGE INDICATION
NOTE:
DECIBEL FUNCTION
IN USE
RELATIVE FUNCTION
IN USE
Position
of decimal point dependent
on range selected.
/oo o o
NOTE: This display will appear
if the switches
of the 8050A are set in
an improper
configuration (e.g. DC V
20 MO)
2-4
80S0A IMPROPER SWITCH SETTING
Figure 2-2. Liquid Crystal Display

Table 2-2. Maximum Input Signal Limits
OPERATION
AC/DC VOLTAGE
FUNCTiON RANGE INPUT MAXIMUM INPUT
SELECTED
SELECTED
TERMiNALS
OVERLOAD
DC
ALL RANGES 1000V
dc or peak ac
V
V/krllS
or 20V, 200V, 750V
and
750V rrns continous or 107V·Hz
dB
AC
COMMON
2V, 200 rnV 750V
rrns for no longer than 15 seconds or 107V·Hz
DC
Double fuse protected: 2A, 250V fuse in
rnA
or
ALL RANGES rnA and COMMON
series with a3A, 600V fuse
AC
V/krllS and
kQ or S ALL RANGES COMMON 500V dc or
ac rrns
VOLTAGE, LINEAR (V)
1. SELECT RANGE --------------..
2. SELECT FUNCTION ---..~- ____
3. CONNECT TEST LEADS __ -L._--!---J
CIRCUIT
RELATIVE
':0
Off
..
r POWER
D~
Off
...
Figure 2-3. AC/OC Voltage Operation
2-5

OPERATION
AC/DC VOLTAGE
CURRENT (mA)
1. SELECT RANGE ---------------'\
2. SELECT FUNCTION
4. BREAKCIRCUIT ---:':-_-J
5. PLACE 8050A mSERIES __ ......L. -J
Figure 2·4. AC/DC Current Operation
2-6
RELATIVE
':'0
Off
..
POWER
D~
OFF
...

2-26. Resistance (0)
2-27. Figure 2-5 describes how to operate theS050A for
resistance measurements. When
kO is selected, erroneous
measurements can occur if power
is present in the
resistance being measured. Ensure that power
is removed
before measuring in-circuit resistances. The AC/
DC
function switch has no effect during resistance
measurements.
2·28. Conductance (S=1/Q)
2-29. Figure 2-6 describes how to operate the S050A for
conductance measurements. When
S=I/0 is selected,
two ranges
of measurements are available, 2 ms and 200
nS.
To select either range, press both range switches
(above the grey-shaded area) simultaneously.
2-30. Diode Test
2-31. Figure 2-7 describes how to operate the S050A for
diode tests. The three resistance ranges with the diode
symbol beside the range value provide ameasurement
OPERATION
RELATIVE
voltage sufficient to cause asilicon junction to conduct.
These ranges (2 kO,
200 kO and 20 MO) can be used to
check silicon diodes and transistors. The 2kO resistance
range
is the preferred diode and transistor testing range
and
is labeled with the largest diode symbol(..... ). For a
silicon diode, the typical forward bias voltage (on the 2
kO i* range) is 0.6V. Areversed bias silicon diode
should display the overrange indicator(on the 2kO
....
range).
2-32. Relative (RELATIVE)
2-33. Figure 2-8 describes how to operate the S050A for
relative measurements. The relative function stores a
reading as
an offset or relative reference value. When the
RELATIVE switch
is set to ON during ameasurement,
the value of that measurement
is stored, and the REL
(relative reference) annunciatorappearstothe right ofthe
zeroed display. Subsequent measurements (in the same
function and range) are displayed as the difference
between the measured value and the stored relative
reference.
RESISTANCE (kO)
1. DE-ENERGIZE CIRCUIT TO BE MEASURED
2. SELECT RANGE ---------
3. SELECT FUNCTION -----,.
4. CONNECT TEST LEADS
LOW
(-) --F===?/r+--~~ 2
\
8050A IIGITAl MUI IMETER
RELATIVE
.2:0
OFF
..
POWER
0.2!
OFF
..
Figure 2-5. Resistance Operation
2-7