HP 3465B Service manual

OPERAT ING AND SERVICE MANUAL
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HEWLETT^ PACKARD

OPERATING AND SERVICE MANUAL
MODEL 3465B
MULTIMETER
Serial Numbers; 1530A00101 and greater
IMPORTANT NOTICE
Any changes made in instruments manufactured after this printing
will be found in a "Manual Changes" supplement supplied with this
manual . Be sure to examine this supplement, if one exists for this
manual, for any changes which apply to your instrument and record
these changes in the manual.
If the Serial Number of your instrument is lower than the one on
this title page, the manual contains revisions that do not apply to
your instrument. Backdating information given in the manual adapts
it to earlier instruments.
Where practical, backdating information is integrated into the text,
parts list and schematic diagrams. Backdating changes are denoted
by a delta sign. An open delta (A) or lettered delta (A/i^) on a given
page refers to the corresponding backdating note on that page.
Backdating changes not integrated into the manual are denoted by
a numbered delta (A-j) which refers to the corresponding change In
the Backdating Section (Section VI I I).
A This symbol is an international symbol meaning "refer to the
Operating and Service Manual." The symbol flags important
operating instructions in Section l it.
WARNING
1
To prevent potential fire or shock hazard, do not expose
equipment to rain or moisture.
Manual Part No. 03465-90010
Microfiche Part No. 03465-90060
Copyright Hewlett-Packard Company 1976
P.O. Box 301, Loveland, Colorado 80537 U.S.A.
Printed: August 1976

HEWLETT [hp: PACKARD
"0
CERTIFICATION
Hewlett-Packard Company certifies that this instrument met its published
specifications at the time of shipment from the factory. Hewlett-Packard
Company further certifies that its calibration measurements are traceable to the
United States National Bureau of Standards, to the extent allowed by the
Bureau's calibration facility, and to the calibration facilities of other
International Standards Organization members.
WARRANTY AND ASSISTANCE
This Hewlett-Packard product is warranted against defects in materials and
workmanship for a period of one year from the date of shipment, except that
in the case of certain components, if any, listed in Section I of this operating
manual, the warranty shall be for the specified period. Hewlett-Packard will, at
its option, repair or replace products which prove to be defective during the
warranty period provided they are returned to Hewlett-Packard, and provided
the proper preventive maintenance procedures as listed in this manual are
followed. Repairs necessitated by misuse of the product are not covered by this
warranty. NO OTHER WARRANTIES ARE EXPRESSED OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OE
MERCHANTABILITY AND EITNESS EOR A PARTICULAR PURPOSE.
HEWLETT-PACKARD IS NOT LIABLE EOR CONSEQUENTIAL DAMAGES.
If this product is sold as part of a Hewlett-Packard integrated instrument
system, the above warranty shall not be applicable, and this product shall be
covered only by the system warranty.
Service contracts or customer assistance agreements are available for
Hewlett-Packard products.
Eor any assistance, contact your nearest Hewlett-Packard Sales and Service
Office. Addresses are provided at the back of this manual.

Model 3465B
Table of Contents
TABLE OF CGIMTEIMTS
Section
I. GENERAL INFORMATION
1-1. Introduction
1-3. Description
1-5. Specifications
1-7. Instrument and Manual Identification . . ..
1-9. Options
1-11. Warranty Exceptions
1-13. Accessories
1-15. Safety Considerations
Page
1
Section Page
II. INSTALLATION 2-1
2-1. Introduction 2-1
2-3. Initial Inspection 2-1
2-5. Power Requirements 2-1
2-7. Grounding Requirements 2-1
2-10. Environmental Requirements 2-1
2-12. Repackaging for Shipment 2-1
2-16. Power Cords and Receptacles 2-1
Section Page
III. OPERATING INSTRUCTIONS 3-1
3-1. Introduction 3-1
3-3. Front Panel Features 3-1
3-5. Turn-on and Warm-up 3-1
3-7. Internal Battery Voltage Measurement
and Recharging 3-1
3-9. Low Battery Voltage Detection 3-1
3-11. Overload Indication 3-1
3-13. AC Voltage Measurements 3-1
3-14. AC Voltage Ranges 3-1
3-16. DC Voltage Measurements 3-2
3-17. 10 mV Range Zero Adjust 3-2
3-19. DC Voltage Ranges 3-2
3-21. Current Measurements 3-3/3-4
3-23. AC Current Ranges 3-3/3-4
3-25. DC Current Ranges 3-3/3-4
3-27. Ohms Measurements 3-3/3-4
3-28. Ohmmeter Ranges 3-3/3-4
3-30. Ohmmeter Reference Current 3-3/3-4
Section Page
IV. THEORY OF OPERATION 4-1
4-1. Introduction 4-1
4-3. Description 4-1
4-6. Simplified Theory 4-2
4-8. Signal Conditioning 4-2
4-18. Analog-to-Digital (A-D) Converter 4-3
4-26. Logic Section 4-4
4-35. Display 4-4
4-37. Power Supply 4-5
4-39. Detailed Theory 4-5
4-41. Precision Resistor Pack (R7 5) 4-5
Section Page
4-43. Ohms Converter 4-5
4-50. AC-to-DC Converter 4-6
4-56. A-D Conversion Using a
Monopolar Reference 4-6
4-64. Data Accumulator 4-8
4-69. Display 4-8
4-72. Power Supply 4-10
4-78. -t 10 V Series Voltage Regulation. . 4-11/4-12
4-80. Battery Low-Voltage Detection . . . 4-11/4-12
Section Page
V. MAINTENANCE 5-1
5-1. Introduction 5-1
5-3. Test Equipment Required 5-1
5-5. Performance Tests 5-1
5-6. DC Voltmeter Accuracy Test 5-1
5-8. DC Ammeter Accuracy Test 5-1
5-10. Ohms Accuracy Test 5-2
5-12. AC Voltage Accuracy Test 5-2
5-14. AC Ammeter Accuracy Test 5-2
5-16. Alternate AC Ammeter Accuracy Test
(200 mA/2000 mA, 40 Hz to 1 kHz) .. 5-4
5-19. AC Normal Mode Rejection Test 5-5
5-21. AC Effective Common-Mode
Rejection Test 5-6
5-23. DC Voltmeter Input Resistance Test. ... 5-6
5-25. AC Voltmeter Input Impedance Test . . . 5-6
5-27. Adjustment Procedures 5-8
5-29. Disassembly Procedure 5-8
5-30. Power Supply Adjustment 5-9
5-34. Input Amplifier Adjustments 5-9
5-37. Ohms Converter Adjustments
(R58 and R69) 5-10
5-39. AC-DC Converter Adjustments 5-10
Section Page
VI. REPLACEABLE PARTS 6-1
6-1. Introduction 6-1
6-4. Ordering Information 6-1
6-6. Non-Listed Parts 6-1
6-8. Parts Changes 6-1
6-10. Proprietary Parts 6-1
Section Page
VII. TROUBLESHOOTING AND CIRCUIT
DIAGRAMS 7-1
7-1. Introduction 7-1
7-3. Schematic Diagrams 7-1
7-5. Preliminary Check 7-1
7-6. Visual Inspection 7-1
7-8. Preliminary Troubleshooting 7-1
7-11. Analog/Digital Isolation 7-1

Table of Contents
Model 3465B
Section Page
7-13. Analog Troubleshooting 7-1
7-14. Analog Isolation 7-1
7-18. Power Supply Faults 7-2
7-20. Signal Conditioning Faults 7-3
7-26. Analog-to-Digital Converter Faults 7-3
7-29. Integrator/Slope Amplifier/
Comparator/Auto-Zero 7-3
7-31. Digital Troubleshooting 7-4
7-33. Display and Display Driver Verification. . 7-4
Section
7-35.
7-37.
7-40.
7-42.
7-44.
Page
Display and Display Driver Quick Test .. 7-4
Display and Display Driver Verification
and Troubleshooting Test 7-5
Polarity, Zero Detect and
Clock Circuit Verification 7-5
Analog Switch Lines and Control State
Counter Verification 7-5
Data Accumulator Input/Output
Verification 7-5
LIST OF TABLES
Table Page
Table
1-1. Specifications
1-2
5-6.
1-2. General Information . . .1-3/1-4
3-1. Ohmmeter Current Through Unknown ...
. .3-3/3-4
5-7.
4-1. Display Interface Connections
4-9
5-1. Test Equipment Required
5-0
5-8.
5-2. DC Voltmeter Accuracy Test
5-1
5-3. DC Ammeter Accuracy Test
5-2
5-9.
5-4. Ohms Accuracy Test
5-2
6-1.
5-5. AC Voltage Accuracy Test
5-3
6-2.
6-3.
Page
AC Ammeter Accuracy Test, 200 /rA
through 20 mA Ranges 5-4
AC Ammeter Accuracy Test, 200 mA and
2000 mA Ranges 5-5
AC Ammeter Accuracy Test 200 mA and
2000 mA Ranges 5-5
Power Supply Jumpers 5-10
Standard Abbreviations 6-1
Code List of Manufacturers 6-2
Replaceable Parts 6-3
LIST OF ILLUSTRATIONS
Figure
2-1. Power Receptacles 2-2
3-1. Front Panel Features 3-2
4-1. Basic Block Diagram and Measurement
Sequence 4-1
4-2. Simplified Diagram, Ohms Converter 4-2
4-3. Block Diagram, AC-to-DC Converter 4-3
4-4. Block Diagram, Power Supply 4-5
4-5. Over-Voltage Protection Circuit 4-5
4-6. Basic Diagram, AC Converter Amplifier 4-6
4-7. Functional Diagram, A-D Converter 4-7
4-8. Data Accumulator 4-9
4-9. Basic Diagram, DC-to-DC Converter 4-10
Figure Page
4-10. Simplified Diagram, DC-to-DC Converter 4-10
5-1. DC Ammeter Accuracy Test 5-1
5-2. Ohms Accuracy Test 5-2
5-3. AC Ammeter Accuracy Test 200 /lA through
20 m A Range 5-3
5-4. AC Ammeter Accuracy Test
200 mA and 2000 mA 5-5
5-5. AC Normal-Mode Rejection Test 5-6
5-6. AC Kffective Common-Mode Rejection Test. .. . 5-6
5-7. DC Voltmeter Input Resistance Test 5-7
5-8. AC Voltmeter Input Impedance Test 5-7
5-9. Multimeter Adjustment Location 5-8

Model 3465 B
Seelion 1
SECTION I
GENERAL INFORIVIATION
1-1. IIMTRODUCTIOW.
1-2. This section contains general information concerning
the -hp- Model 3465B Multimeter. Included is an instru
ment description, specifications, information about instru
ment and manual identification, option and accessory in
formation and safety considerations.
1-3. DESCRIPTION.
1-4. The -hp- Model 3465B Multimeter is a 4-1/2 digit, five
function digital multimeter. The five functions are dc volts,
ac volts, dc current, ac current and ohms. Measurements
can be made to four significant digits with a sample rate of
2-1/2 readings per second. Throughout this manual, the
3465B Multimeter will be referred to as Multimeter.
1-5. SPECIFICATIONS.
1-6. Instrument specifications are listed in Table 1-1. These
specifications are the performance standards or limits
against which the instrument is tested. Any change in the
specifications due to manufacturing, design or traceability
to the U.S. National Bureau of Standards will be covered by
a change sheet. Additional information describing the oper
ating characteristics are not specifications but are supple
mental information for the user.
1-7. INSTRUMENT AND MANUAL IDENTIFICATION.
1-8. Hewlett-Packard uses a two-section serial number. The
first section (prefix) identifies a series of instruments. The
last section (suffix) identifies a particular instrument within
the series. If a letter is included with the serial number, it
identifies the country where the instrument was manufac
tured. This manual is kept up-to-date with the instrument
at all times by revision. If the serial prefix of your
instrument differs from the one on the title page of this
manual, refer to Section VIll for backdating information
that will adapt this manual to your instrument. All corres
pondence with Hewlett-Packard should include the
complete serial number.
1-9. OPTIONS.
1-10. The following is a list of the options available for the
multimeter. Multimeter options are available to allow oper
ation from various line voltages.
Option
100
115
210
230
910
Description
86 - 106 V ac 48 - 440 Hz
104 - 127 V ac 48 - 440 Hz
190 — 233 V ac 48 — 440 Hz
208 - 250 V ac 48 - 440 Hz
An additional Operating and
Service Manual
1-11. Warranty Exceptions.
1-12. Batteries are warranted for 90 days.
1-13. ACCESSORIES.
1-14. The following accessories are available to extend the
usefulness of your Multimeter:
a. Model 11096B RF Probe, 100 kHz to 500 MHz
(down 3 dB at 10 kHz and 700 MHz), for use on the 10 V
and 100 V ranges in the DCV function only.
b. Model 11002A Test leads, dual banana to dual alli
gator.
c. Model 11003A test leads, dual banana to probe and
alligator.
d. Model llOOOA dual banana to dual banana, 44 in.
e. Model 341 lOA soft vinyl carrying case.
f. Model 3411 lA HV Probe, 40 kV dc.
g. Model 34112A Touch — Hold Input Probe.
1-15. SAFETY CONSIDERATIONS.
1-16. This operating and service manual contains cautions
and warnings alerting the user to hazardous operating and
maintenance conditions. This information is flagged by a
camion or warning heading and/or the symbol A . The
A symbol appears on the front panel and is an inter
national symbol meaning "refer to the Operating and
Service Manual' . This symbol flags important operating
instructions located in Section 111. To ensure the safety of
the operating and maintenance personnel and retain the
operating condition of the instrument, these instructions
must be adhered to.
1-1

Section I
Model 3465 B
Table 1-1. Specifications.
DC VOLTMETER
Ranges: 20 mV, 200 mV, 2 V, 20 V, 200 V, 1,000 V
Maximum Input: 1,000 V (DC + Peak AC)
Accuracy (1 year + 23°C ± 5°C):
Range Specification
20 mV
200 mV through 200 V
1000 V
± (0.03% of reading + 2 counts)
± (0.02% of reading + 1 count)
± (0.025% of reading + 1 count)
Temperature Coefficient (0°C to 50°C): ± 0.003% of Read-
ing/°C
Effective Common-Mode Rejection (with 1 k£7 imbalance in
either lead):
AC: > 120dBat 50/60 Hz ± 0.1%
AC Normal-Mode Rejection:
> 60 dB at 50/60 Hz + 0.1 %
Input Resistance:
20 mV through 2 V ranges: (80% R.H.) ^ 1o' ^ rz
20 V through 1,000 V ranges: 10 Mfi ± 1 %
AC VOLTMETER
Ranges: 200 mV, 2 V, 20 V, 200 V, 500 V (500 V Max)
Qverrange: The maximum reading decreases linearly from
19,999 at 10 kHz to 10,000 at 20 kHz.
Accuracy: 1 year + 23°C ± 5°C)
500 V
(500 V rms)
MAX
± (0.5% of reading + 5 counts)
200 V
20 V
2 V
200 mV
± (0.1 5% of reading
-I- 5 counts)
± (0.5% of reading
+ 1 5 counts)
-+■
40 IK 2 K 10 K 20 K
INPUT VOLTAGE FREQUENCY (Hz)
Temperature Coefficient (O^C to 50^0: ± (0.005% of Reading
+ .2 counts)/°C
Input Impedance: 1 M ± 1 % shunted by < 100 pF
DC AMMETER
Ranges: 200 nA. 2 mA, 20 mA, 200 mA, 2,000 mA
Maximum Input: 2 A from < 250 V source
Protection: 2 A/250 V fuse (normal blow)
Voltage Burden:
Range
200 mA - 200 mA
2,000 mA
Max Burden at Full Scale
< 250 mV
< 700 mV
Accuracy: 1 year-i-23°C ± 5°C)
Range Specification
200 mA, 2 mA
20 mA
200 mA, 2000 mA
± (0.07% of reading + 1 count)
+ (0.11 % of reading + 1 count)
± (0.6% of reading 1 count)
Temperature Coefficient (0®C to 50*^0:
Specification
Range
± (%of Reading)/°C
200 mA
± 0.006%
2 mA, 20 mA
± 0.004%
200 mA, 2,000 mA
± 0.01%
AC AMMETER
Ranges: 200 mA, 2 mA, 20 mA, 200 mA, 2,000 mA
Qverrange: The maximum reading decreases linearly from
19,999 at 10 kHz to 10,000 at 20 kHz.
Accuracy: (1 year,+ 23°C ± 5°C)
(% of Reading + Counts)
2000 mA
^ 200 mA f ± (0.8%
+ 5)
UJ
20 mA
2 mA
cc
a:
g 200 mA
u
<
± (0.4%
+ 5)
± (0.65%
- + 5)
± (0.25% + 5)
± (0.6%
-•-15)
40 IK 2 K 10 K 20 K
INPUT CURRENT FREQUENCY (Hz)
Temperature Coefficient (0°C to 50°C); ± 0.01% of Read-
ing/°C.
Protection: 2A/250 V fuse (normal blow)
Voltage Burden:
Range
Max Burden at Full Scale
200 mA - 200 mA
< 250 mV
2,000 mA
< 700 mV
OHMMETER
Ranges: 200 2 kn, 20 kfi, 200 kfi, 2,000 kJ2, 20 Mr2
Accuracy: (1 year + 23°C ± B'^C)
Range
200 n
2 kf2 through 2 MS7
20 Mn
Specification
± (0.02% of reading -t- 2 counts)
+ (0.02% of reading + 1 count)
+ (.1 % of reading + 1 count)
Temperature Coefficient {0°C to 50®C)
Range
Specificatio
200 n through 2 Mil
20 MQ
n
± (% of Reading)/°C
± 0.0015%
± 0.004%
1-2

Model 3465 B
Section 1
Table 1-2. General Information.
Maximum Input Voltages:
Between Input HIGH (V, H.) and COM:
Function Max Voltage
DC Volts
1000 V (dc -1- peak ac)
AC Volts 600 V dc; 500 V ac rms;
800 V peak ac
Ohms 350 V (dc + peak ac)
Between AMPS (A), HIGH (V, and COM terminals and
ground:
± 500 V (dc + peak ac}
Reading Rate: 2.5 samples per second
Overload Indication: Display Blanks except for overrange "1"
and decimal point (also polarity sign on DCV or DCA FUNC
TIONS).
Ohms Terminal Characteristics:
Configuration: 2 wire
Open-circuit voltage: < 5 V max.
Overload protection; 350 V (dc + peak ac)
Nominal current through unknown resistance:
Range
Current
200 n 1 mA
2 kJ2 1 mA
20 kii
10 mA
200 ka
IOmA
2000 kn
1 juA
20 Mn 0.1 mA
Power Requirements:
Power: AC Line; 48 — 440 Hz
86 - 106 V Option 100
104 - 127 V Option 115
190 -233 V Option 210
208 -250 V Option 230
Battery (Rechargeable NiCad): 6 hours minimum continuous
operation
Recharge Time: 8 hours (instrument off)
Total Instrument Power Dissipated:
Instrument on, Battery Operation: < 1 watt
Instrument on, Line Operation: < 10 VA
Battery Test: Depress DCV and 10 Mf2: Recharge NiCad bat
teries if the display reading is < 0.380.
Environmental Considerations:
Operating temperature: 0®C to 40°C (32°F to 104'^F)
Humidity range: 95% at 40°C
Storage temperature: - 20°C to + 50°C (-4°F to 122°F)
1-3/1-4

Model 3465B
Section II
SECTION II
INSTALLATION
2-1. INTRODUCTION.
2-2. This section contains information and instructions for
the installation and shipping of the Multimeter. Included
are initial inspection procedures, power and grounding
requirements, environmental information and instructions
for repackaging for shipment.
2-3. INITIAL INSPECTION.
2-4. This instrument was carefully inspected both mechani
cally and electrically before shipment. It should be free of
mars or scratches and in f)erfect electrical order upon
receipt. To confirm this, the instrument should be inspec
ted for physical damage in transit, and the electrical
performance should be tested using the performance tests
outlined in Section V. If there is damage or deficiency, see
the warranty inside the front of this manual.
2-5. POWER REQUIREMENTS.
2-6. This Multimeter will operate on ac line voltage or from
internal rechargeable NiCad batteries. AC line voltage
options are described in Table 1-2.
lOd'^F) or stored outside the ambient temperature range of
- 20OC to + SQOC (- 40F to 1220F).
A
Verify that the ac power source matches the
power requirement of the instrument as marked
on the option label affixed to the rear of the
instrument.
2-7. GROUNDING REQUIREMENTS.
2-8. To protect operating personnel, the National Electrical
Manufacturer's Association (NEMA) recommends that the
instrument panel and cabinet be grounded. Multimeters are
equipped with a three-conductor power cable which, when
plugged into an appropriate receptacle, grounds the instru
ment. The offset pin on the power cable is the ground wire.
2-9. To preserve the protection feature when operating
from a two-contact outlet, use a three-prong to two-prong
adapter and connect the green pigtail on the adapter to
power line ground.
2-10. ENVIRONMENTAL REQUIREMENTS.
2-11. The Multimeter should not be operated outside the
ambient temperature range of O'^C to 40°C (32°F to
WARNING
To prevent potential electrical or fire hazard,
do not expose equipment to rain or moisture.
2-12. REPACKAGING FOR SHIPMENT.
2-13. The following paragraphs contain a general guide for
repackaging the instrument for shipment. Refer to Para
graph 2-14 if the original container is to be used; 2-15 if it
is not. If you have any questions, contact your nearest -hp-
Sales and Service Office (see back of Manual for office loca
tions).
NOTE
If the instrument is to be shipped to Hewlett-
Packard for service or repair, attach a tag to
the instrument identifying the owner and indi
cating the service or repair to be accomplished.
Include the model number and full serial
number of the instrument. In any correspon
dence, identify the instrument by model num
ber and full serial number.
2-14. Hace instrument in original container with appropri
ate packing material and seal well with strong tape or metal
bands. If original container is not available, one can be
purchased from your nearest -hp- Sales and Service Office.
2-15. If original container is not to be used, proceed as
follows:
a. Wrap instrument in heavy paper or plastic before
placing in an inner container.
b. Place packing material around all sides of instrument
and protect panel face with cardboard strips.
c. Place instrument and inner container in a heavy
carton or wooden box and seal with strong tape or metal
bands.
2-16. POWER CORDS AND RECEPTACLES.
2-17. Figure 2-1 illustrates the plug cap configurations that
2-1

Section II
Model 3465B
are available to provide ac power to the Multimeter. The
-hp- part number shown directly below each plug cap draw
ing is the part number for the power cord set equipped with
the appropriate mating plug for that receptacle. The appro
priate power cord should be provided with each instrument.
However, if a different power cord set is required, notify
the nearest -hp- Sales and Service Office and a replacement
cord will be provided. The instrument ac power input
receptacle and cord set appliance coupler meet the safety
specifications set by the International Commission on Rules
for the Approval of Electrical Equipment (GEE 22).
8120-1348 8120-0698
126V-6A- 260V-6A*
■UL LISTED FOR USE IN THE UNITED STATES OF AMERICA
Figure 2-1. Power Receptacles.
2-2