ADCMT 7481 User manual

MANUAL NUMBER
ADC CORPORATION
C
All rights reserved. Printed in Japan
7481/7482
Digital Multimeter
Operation Manual
FOA-00000191A02
Applicable Models
7481
7482
First printing August 1, 2023
2023
Cover

Safety-1
FOE-ANZENA01
Safety Summary
To ensure thorough understanding of all functions and to ensure efficient use of this instrument, please read the
manual carefully before using. Note that ADC Corporation (hereafter referred to as ADC) bears absolutely no
responsibility for the result of operations caused due to incorrect or inappropriate use of this instrument.
If the equipment is used in a manner not specified by ADC, the protection provided by the equipment may be
impaired.
• Warning Labels
Warning labels are applied to ADC products in locations where specific dangers exist. Pay
careful attention to these labels during handling. Do not remove or tear these labels. If you have
any questions regarding warning labels, please ask your nearest ADC dealer. Our address and
phone number are listed at the end of this manual.
Symbols of those warning labels are shown below together with their meaning.
DANGER: Indicates an imminently hazardous situation which will result in death or serious
personal injury.
WARNING: Indicates a potentially hazardous situation which will result in death or serious
personal injury.
CAUTION: Indicates a potentially hazardous situation which will result in personal injury or
a damage to property including the product.
• Basic Precautions
Please observe the following precautions to prevent fire, burn, electric shock, and personal
injury.
• Use a power cable rated for the voltage in question. Be sure however to use a power cable
conforming to safety standards of your nation when using a product overseas.
• When inserting the plug into the electrical outlet, first turn the power switch OFF and then
insert the plug as far as it will go.
• When removing the plug from the electrical outlet, first turn the power switch OFF and then
pull it out by gripping the plug. Do not pull on the power cable itself. Make sure your hands
are dry at this time.
• Before turning on the power, be sure to check that the supply voltage matches the voltage
requirements of the instrument.
• Connect the power cable to a power outlet that is connected to a protected ground terminal.
Grounding will be defeated if you use an extension cord which does not include a protective
conductor terminal.
• Be sure to use fuses rated for the voltage in question.
• Do not use this instrument with the case open.
• If there is any abnormality such as abnormal heart, smoke, smell or noise, immediately stop
using the instrument, turn off the power and disconnect the plug from the outlet.
目次

Safety Summary
Safety-2 FOE-ANZENA01
• Do not place anything on the product and do not apply excessive pressure to the product.
Also, do not place flower pots or other containers containing liquid such as chemicals near
this product.
• When the product has ventilation outlets, do not stick or drop metal or easily flammable
objects into the ventilation outlets.
• When using the product on a cart, fix it with belts to avoid its drop.
• When connecting the product to peripheral equipment, turn the power off.
• Caution Symbols Used Within this Manual
Symbols indicating items requiring caution which are used in this manual are shown below
together with their meaning.
DANGER: Indicates an item where there is a danger of serious personal injury (death or
serious injury).
WARNING: Indicates an item relating to personal safety or health.
CAUTION: Indicates an item relating to possible damage to the product or instrument or
relating to a restriction on operation.
• Safety Marks on the Product
The following safety marks can be found on ADC products.
: ATTENTION - Refer to manual.
: Protective ground (earth) terminal.
: DANGER - High voltage.
: CAUTION - Risk of electric shock.
• Replacing Parts with Limited Life
The following parts used in the instrument are main parts with limited life.
Replace the parts listed below before their expected lifespan has expired to maintain the
performance and function of the instrument.
Note that the estimated lifespan for the parts listed below may be shortened by factors such as
the environment where the instrument is stored or used, and how often the instrument is used.
The parts inside are not user-replaceable. For a part replacement, please contact the ADC sales
office for servicing.
Each product may use parts with limited life.
For more information, refer to the section in this document where the parts with limited life are
described.

Safety Summary
Safety-3
FOE-ANZENA01
Main Parts with Limited Life
• Hard Disk Mounted Products
The operational warnings are listed below.
• Do not move, shock and vibrate the product while the power is turned on.
Reading or writing data in the hard disk unit is performed with the memory disk turning at a
high speed. It is a very delicate process.
• Store and operate the products under the following environmental conditions.
An area with no sudden temperature changes.
An area away from shock or vibrations. An area free from moisture, dirt, or dust.
An area away from magnets or an instrument which generates a magnetic field.
• Make back-ups of important data.
The data stored in the disk may become damaged if the product is mishandled. The hard disc
has a limited life span which depends on the operational conditions. Note that there is no
guarantee for any loss of data.
• Precautions when Disposing of this Instrument
When disposing of harmful substances, be sure dispose of them properly with abiding by the
state-provided law.
Harmful substances: (1) PCB (polycarbon biphenyl)
(2) Mercury
(3) Ni-Cd (nickel cadmium)
(4) Other
Items possessing cyan, organic phosphorous and hexadic chromium
and items which may leak cadmium or arsenic (excluding lead in
solder).
Example: fluorescent tubes, batterie
Part name Life
Unit power supply 5 years
Fan motor 5 years
Electrolytic capacitor 5 years
LCD display 6 years
LCD backlight 2.5 years
Memory backup battery 5 years

Safety-4 FOE-ANZENA01
Environmental Conditions
This instrument should be only be used in an indoor area which satisfies the following conditions:
• An area free from corrosive gas
• An area away from direct sunlight
• A dust-free area
• An area free from vibrations
• Altitude of up to 2000 m
Figure-1 Environmental Conditions
• Operating position
Figure-2 Operating Position
• Storage position
Figure-3 Storage Position
• The classification of the transient over-voltage, which exists typically in the main power supply, and the
pollution degree is defined by IEC61010-1 and described below.
Impulse withstand voltage (over-voltage) category II defined by IEC60364-4-443
Pollution Degree 2
Corrosive
gas
Direct sunlight
Dust
Vibration
The instrument must be used in a
horizontal position.
To prevent the internal temperature
from rising, cooling fans are installed
in some instruments.
The air vents on the case must be
unblocked.
A clear space of 10 centimeters or more
must be kept around the air vents.
Front
This instrument should be stored in a horizontal
position.
When placed in a vertical (upright) position for
storage or transportation, ensure the instrument is
stable and secure.
-Ensure the instrument is stable.
-Pay special attention not to fall.
Front

Safety-5
FOE-ANZENA01
Types of Power Cable
Replace any references to the power cable type, according to the following table, with the appropriate power cable
type for your country.
Plug configuration Standards Rating, color
and length
Model number
(Option number)
PSE: Japan
Electrical Appliance and
Material Safety Law
125 V at 7 A
Black
2 m (6 ft)
Straight: A01402
Angled: A01412
UL: United States of America
CSA: Canada
125 V at 7 A
Black
2 m (6 ft)
Straight: A01403
(Option 95)
Angled: A01413
CEE: Europe
DEMKO: Denmark
NEMKO: Norway
VDE: Germany
KEMA: The Netherlands
CEBEC: Belgium
OVE: Austria
FIMKO: Finland
SEMKO: Sweden
250 V at 6 A
Gray
2 m (6 ft)
Straight: A01404
(Option 96)
Angled: A01414
SEV: Switzerland 250 V at 6 A
Gray
2 m (6 ft)
Straight: A01405
(Option 97)
Angled: A01415
SAA: Australia, New Zealand 250 V at 6 A
Gray
2 m (6 ft)
Straight: A01406
(Option 98)
Angled: ---------
BS: United Kingdom 250 V at 6 A
Black
2 m (6 ft)
Straight: A01407
(Option 99)
Angled: A01417
CCC: China 250 V at 10 A
Black
2 m (6 ft)
Straight: A114009
(Option 94)
Angled: A114109

TABLE OF CONTENTS
7481/7482 Digital Multimeter Operation Manual
C-1
1. PREFACE ............................................................................................................................. 1-1
1.1 Product Overview ...................................................................................................................... 1-1
1.2 Supplied Accessories ................................................................................................................. 1-2
1.3 Optional Accessories .................................................................................................................. 1-2
1.4 Operating Environment .............................................................................................................. 1-3
1.4.1 Environmental Conditions .................................................................................................1-3
1.4.2 Positioning ......................................................................................................................... 1-4
1.5 Power Supply ............................................................................................................................. 1-5
1.5.1 Power Conditions ............................................................................................................... 1-5
1.5.2 Changing Power Voltage, and Checking or Replacing Power Fuse .................................. 1-5
1.5.3 Connecting Power Cable .................................................................................................... 1-7
1.6 Input Cable ................................................................................................................................. 1-8
1.7 Replacing Protection Fuses ........................................................................................................ 1-10
1.8 Cleaning, Storage, and Transport Methods ................................................................................ 1-11
1.8.1 Cleaning ............................................................................................................................. 1-11
1.8.2 Storage ............................................................................................................................... 1-11
1.8.3 Transport ............................................................................................................................ 1-11
1.9 Precautions ................................................................................................................................. 1-12
1.10 Calibration .................................................................................................................................. 1-12
1.11 EMI and EMC Measures ............................................................................................................ 1-12
1.12 Life Limited Parts ...................................................................................................................... 1-13
1.13 Product Disposal and Recycling ................................................................................................ 1-14
2. PANEL DESCRIPTION ................................................................................................. 2-1
2.1 Front Panel ................................................................................................................................. 2-1
2.1.1 Power Switch ..................................................................................................................... 2-1
2.1.2 Measurement Function Selection Keys .............................................................................. 2-2
2.1.3 Measurement Range Selection Keys .................................................................................. 2-2
2.1.4 Sampling Keys ................................................................................................................... 2-2
2.1.5 Entry Keys .......................................................................................................................... 2-3
2.1.6 Memory Keys ..................................................................................................................... 2-3
2.1.7 Calculation Keys ................................................................................................................ 2-3
2.1.8 Input Keys .......................................................................................................................... 2-3
2.1.9 Display ............................................................................................................................... 2-4
2.2 Rear Panel .................................................................................................................................. 2-6
3. BASIC OPERATION ....................................................................................................... 3-1
3.1 Power ON and Self-Test ............................................................................................................ 3-1
3.2 Initialization (Initialization of Measurement Conditions) ......................................................... 3-2
3.2.1 Backup of Measurement Conditions .................................................................................. 3-2
3.2.2 Initial States ........................................................................................................................ 3-2
3.2.3 How to Initialize ................................................................................................................. 3-5
3.3 Switching Input Terminals ......................................................................................................... 3-6
3.4 Opening or Short-Circuiting LOW-GUARD ............................................................................. 3-6
3.5 DC Voltage Measurement (DCV) .............................................................................................. 3-7
3.5.1 Range Configuration .......................................................................................................... 3-7
3.5.2 Maximum Allowable Input Voltage .................................................................................. 3-7
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TABLE OF CONTENTS
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3.5.3 Input Connection ................................................................................................................ 3-7
3.5.4 Measurement Condition Setting ......................................................................................... 3-8
3.6 Resistance Measurement ............................................................................................................ 3-12
3.6.1 Range Configuration .......................................................................................................... 3-12
3.6.2 Maximum Allowable Input Voltage .................................................................................. 3-12
3.6.3 2-Wire Resistance Measurement (2 WΩ) .......................................................................... 3-13
3.6.4 4-Wire Resistance Measurement (4 WΩ) .......................................................................... 3-13
3.6.5 Resistance Measurement Condition Setting ...................................................................... 3-14
3.7 DC Current Measurement (DCI) ................................................................................................ 3-21
3.7.1 Range Configuration .......................................................................................................... 3-21
3.7.2 Input Connection ................................................................................................................ 3-21
3.7.3 Measurement Condition Setting ......................................................................................... 3-22
3.8 AC Voltage Measurement (ACV) (7482 only) .......................................................................... 3-23
3.8.1 Range Configuration .......................................................................................................... 3-23
3.8.2 Maximum Allowable Input Voltage ................................................................................. 3-23
3.8.3 Input Connection ................................................................................................................ 3-24
3.8.4 Measurement Condition Setting ......................................................................................... 3-24
3.9 AC Current Measurement (ACI) (7482 Only) ........................................................................... 3-28
3.9.1 Range Configuration .......................................................................................................... 3-28
3.9.2 Input Connection ................................................................................................................ 3-28
3.9.3 Measurement Condition Setting ......................................................................................... 3-29
3.10 Frequency/Period Measurement (FREQ/PERIOD) (7482 only) ............................................... 3-33
3.10.1 Input Connection ................................................................................................................ 3-33
3.10.2 Selection between Frequency Measurement and Period Measurement ............................. 3-33
3.10.3 Measurement Condition Setting ......................................................................................... 3-34
3.11 Range Setting ............................................................................................................................. 3-40
3.11.1 When in Auto-Range State ................................................................................................3-40
3.11.2 When in Manual-Range State ............................................................................................ 3-40
3.12 Integration Time/Display Digits Setting .................................................................................... 3-43
3.12.1 Integration Time ................................................................................................................. 3-43
3.12.2 Display Digits .................................................................................................................... 3-45
3.13 Auto-Zero ................................................................................................................................... 3-47
3.14 NULL ......................................................................................................................................... 3-48
3.15 Errors .......................................................................................................................................... 3-50
3.15.1 Panel Display ..................................................................................................................... 3-50
3.15.2 Remote Display .................................................................................................................. 3-50
3.15.3 Error Read-Out from Panel ................................................................................................ 3-51
3.15.4 Error Read-Out by Remote Output .................................................................................... 3-51
3.16 Over-Input Voltage Detection (Alarm) ......................................................................................3-52
3.16.1 Alarm Conditions ............................................................................................................... 3-52
3.16.2 Precautions in Case of Alarm ............................................................................................. 3-53
3.17 Event History ............................................................................................................................. 3-53
3.17.1 Read-Out ............................................................................................................................ 3-54
4. MENU AND FUNCTIONS ............................................................................................ 4-1
4.1 Menu .......................................................................................................................................... 4-1
4.1.1 How to Navigate Menus ....................................................................................................4-1
4.1.2 Menu List ........................................................................................................................... 4-3
4.2 Measurement Function ............................................................................................................... 4-9
4.2.1 DC Voltage Measurement (DCV) ...................................................................................... 4-9

7481/7482 Digital Multimeter Operation Manual
TABLE OF CONTENTS
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4.2.2 DC Current Measurement (DCI) ........................................................................................ 4-10
4.2.3 Resistance Measurement (2 WΩ/4 WΩ) ............................................................................ 4-10
4.2.4 AC Voltage Measurement (ACV) (7482 Only) ................................................................. 4-11
4.2.5 AC Current Measurement (ACI) (7482 Only) ................................................................... 4-12
4.2.6 Frequency/Period Measurement (FREQ/PERIOD) (7482 only) ....................................... 4-13
4.3 Trigger System ........................................................................................................................... 4-14
4.4 Calculation Function .................................................................................................................. 4-14
4.5 Memory Function ....................................................................................................................... 4-15
4.6 Parameter Initialization, Saving and Reading Function ............................................................. 4-15
4.7 Interface ..................................................................................................................................... 4-16
4.8 Maintenance ............................................................................................................................... 4-17
4.9 System ........................................................................................................................................ 4-18
4.9.1 Buzzer Setting .................................................................................................................... 4-18
4.9.2 Display Selection ............................................................................................................... 4-19
4.9.3 Internal Temperature Display ............................................................................................ 4-19
4.9.4 Line Frequency Display ..................................................................................................... 4-20
4.9.5 Date and Time Setting ........................................................................................................ 4-20
4.9.6 Error Queue Display .......................................................................................................... 4-21
4.9.7 Serial Number and Software Revision Display ................................................................. 4-21
4.9.8 Relay Switching Count Display ......................................................................................... 4-21
4.9.9 Event History Display ........................................................................................................ 4-22
5. CALCULATION FUNCTION ....................................................................................... 5-1
5.1 Overview .................................................................................................................................... 5-1
5.2 Digital Filter (D. Filter) .............................................................................................................. 5-5
5.2.1 Smoothing .......................................................................................................................... 5-5
5.2.2 Averaging ........................................................................................................................... 5-6
5.3 Format Calculation (Format) ..................................................................................................... 5-7
5.3.1 Scaling ................................................................................................................................ 5-8
5.3.2 % Deviation (Deviation) .................................................................................................... 5-9
5.3.3 Delta ................................................................................................................................... 5-10
5.3.4 dB Conversion (dB) ........................................................................................................... 5-11
5.3.5 RMS ................................................................................................................................... 5-12
5.3.6 dBm Conversion (dBm) .....................................................................................................5-13
5.3.7 Resistance Temperature Compensation (OHM-TEMP) .................................................... 5-14
5.3.8 RTD .................................................................................................................................... 5-15
5.4 Comparator ................................................................................................................................. 5-17
5.5 Statistical Calculation (Statistics) .............................................................................................. 5-21
6. INTERNAL MEMORY FUNCTION .......................................................................... 6-1
6.1 Overview .................................................................................................................................... 6-1
6.2 Storing and Reading Out Setting Conditions ............................................................................. 6-1
6.2.1 Initial State of Memory ...................................................................................................... 6-2
6.2.2 Saving Setting Conditions .................................................................................................. 6-5
6.2.3 Recalling Setting Conditions .............................................................................................6-6
6.2.4 Setting Conditions Recalled at Power ON ......................................................................... 6-7
6.3 Storing Measurement Data ......................................................................................................... 6-8
6.3.1 Setting Number of Stored Data .......................................................................................... 6-9
6.3.2 Data Storing Ending Conditions ........................................................................................ 6-10
6.3.3 How to Store Measurement Data ....................................................................................... 6-13

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6.4 Recalling Measurement Data ..................................................................................................... 6-14
6.4.1 How to Recall Measurement Data ..................................................................................... 6-14
6.4.2 Calculations on Recalled Data ........................................................................................... 6-14
6.5 Information Reference by Remote Output ................................................................................. 6-16
6.5.1 Stored Data Reference ....................................................................................................... 6-16
6.6 Transfer of Measurement Data to USB Memory ....................................................................... 6-17
6.6.1 Usable USB Memory ......................................................................................................... 6-17
6.6.2 List of Saved Files .............................................................................................................. 6-17
6.6.3 Saving Files ........................................................................................................................ 6-18
6.6.4 Deleting Files ..................................................................................................................... 6-19
7. TRIGGER SYSTEM FUNCTIONS AND USAGE ............................................. 7-1
7.1 Trigger Model (for SCPI Commands) ....................................................................................... 7-1
7.1.1 IDLE State (SCPI) ............................................................................................................. 7-3
7.1.2 INITIATE State (SCPI) ..................................................................................................... 7-3
7.1.3 Arm Layer (SCPI) .............................................................................................................. 7-4
7.1.4 Trigger Layer (SCPI) ......................................................................................................... 7-5
7.2 Trigger Model (For ADC Commands) ...................................................................................... 7-6
7.2.1 IDLE State (ADC) ............................................................................................................. 7-6
7.2.2 INITIATE State (ADC) .....................................................................................................7-6
7.2.3 Arm Layer (ADC) .............................................................................................................. 7-7
7.2.4 Trigger Layer (ADC) ......................................................................................................... 7-8
7.3 Trigger Model (for Panel Operation) ......................................................................................... 7-9
7.3.1 IDLE State (Panel Operation) ............................................................................................ 7-9
7.3.2 INITIATE State (Panel Operation) .................................................................................... 7-9
7.3.3 Arm Layer (Panel Operation) ............................................................................................ 7-10
7.3.4 Trigger Layer (Panel Operation) ........................................................................................ 7-11
7.4 Arm Layer and Trigger Layer .................................................................................................... 7-12
7.4.1 Event Source ...................................................................................................................... 7-12
7.4.2 Edge and Level Setting of Trigger Signal .......................................................................... 7-15
7.4.3 Timer Event ........................................................................................................................ 7-16
7.4.4 Delay Time ......................................................................................................................... 7-16
7.4.5 Event Detection Bypass ..................................................................................................... 7-17
7.4.6 Repeated Processing .......................................................................................................... 7-17
7.4.7 Complete Signal Output ..................................................................................................... 7-18
7.4.8 Trigger System Errors ........................................................................................................ 7-19
7.5 FAST Mode ................................................................................................................................ 7-20
7.5.1 Measurable Functions ........................................................................................................ 7-20
7.5.2 Restrictions in FAST Mode ............................................................................................... 7-20
7.5.3 Measurement Rate .............................................................................................................. 7-21
7.6 Trigger System in FAST Mode .................................................................................................. 7-22
7.6.1 IDLE State .......................................................................................................................... 7-23
7.6.2 INITIATE State .................................................................................................................. 7-24
7.6.3 Arm Layer .......................................................................................................................... 7-24
7.6.4 Trigger Layer ..................................................................................................................... 7-24
7.7 Measurement Data Output Method and Format for FAST Mode .............................................. 7-26
7.8 How to Output Raw Data ........................................................................................................... 7-27
7.9 How to Find True Values ........................................................................................................... 7-28
8. REMOTE CONTROL ...................................................................................................... 8-1

7481/7482 Digital Multimeter Operation Manual
TABLE OF CONTENTS
C-5
8.1 Interface Overview ..................................................................................................................... 8-1
8.1.1 Remote Interface Selection ................................................................................................ 8-1
8.2 GPIB ........................................................................................................................................... 8-2
8.2.1 GPIB Overview .................................................................................................................. 8-2
8.2.2 Precautions when Using GPIB ........................................................................................... 8-3
8.2.3 GPIB Setting ...................................................................................................................... 8-4
8.3 USB ............................................................................................................................................ 8-7
8.3.1 USB Overview ................................................................................................................... 8-7
8.3.2 Connecting with Personal Computer ................................................................................. 8-7
8.3.3 USB Setting ........................................................................................................................ 8-8
8.4 LAN ........................................................................................................................................... 8-9
8.4.1 LAN Overview ................................................................................................................... 8-9
8.4.2 LAN Setting ....................................................................................................................... 8-9
8.4.3 Communication Setting on Computer ................................................................................ 8-10
8.4.4 Network Connection .......................................................................................................... 8-10
8.4.5 IP Connection Check ......................................................................................................... 8-11
8.4.6 Communication Method .................................................................................................... 8-12
8.5 Output Data Format and Query .................................................................................................. 8-13
8.5.1 ASCII Format ..................................................................................................................... 8-13
8.5.2 REAL 64 Format ................................................................................................................ 8-20
8.5.3 Query .................................................................................................................................. 8-20
8.6 Status Register ............................................................................................................................ 8-21
8.6.1 SCPI Status Register Configuration ................................................................................... 8-21
8.6.2 Status Byte Register ........................................................................................................... 8-24
8.6.3 Standard Event Status Register .......................................................................................... 8-27
8.6.4 Measurement Event Register ............................................................................................. 8-28
8.6.5 Questionable Event Register ..............................................................................................8-29
8.6.6 Operation Event Register ................................................................................................... 8-30
8.7 Remote Queue Buffer ................................................................................................................ 8-31
8.8 Command Syntax ....................................................................................................................... 8-33
8.8.1 Case-Sensitivity ................................................................................................................. 8-33
8.8.2 Long Form and Short Form (Applicable to SCPI Commands) ......................................... 8-33
8.8.3 Command Parameters (Applicable to Common Commands and SCPI Commands) ........ 8-33
8.8.3.1 Commands without Parameters ......................................................................................... 8-34
8.8.3.2 Commands with Parameters ...............................................................................................8-34
8.8.4 Query Commands (Applicable to Common Commands and SCPI Commands) ............... 8-36
8.8.5 Layer Structure and Command Description
(Applicable to Common Commands and SCPI Commands) ............................................. 8-37
8.8.6 Command Description (Applicable to ADC Commands) ................................................. 8-40
8.9 Common Commands .................................................................................................................. 8-41
8.10 SCPI Command List .................................................................................................................. 8-42
8.11 ADC Command List .................................................................................................................. 8-64
8.12 3458A-Compatibility ................................................................................................................. 8-81
8.12.1 Compatible Operation ........................................................................................................ 8-81
8.12.2 Status .................................................................................................................................. 8-82
8.12.3 3458 Commands ................................................................................................................ 8-83
8.13 Program Examples ..................................................................................................................... 8-89
9. TROUBLESHOOTING ................................................................................................... 9-1

7481/7482 Digital Multimeter Operation Manual
TABLE OF CONTENTS
C-6
10. MAINTENANCE ................................................................................................................ 10-1
10.1 Precautions for Calibration ........................................................................................................ 10-1
10.2 Devices Required for Calibration .............................................................................................. 10-2
10.3 Calibration Data Protection ........................................................................................................ 10-3
10.3.1 How to Set Calibration Data Protection ............................................................................. 10-4
10.3.2 Passcode Change ................................................................................................................ 10-5
10.4 Calibration Procedures ............................................................................................................... 10-6
10.4.1 Before Calibration .............................................................................................................. 10-6
10.4.2 External Calibration (EXT CAL) ....................................................................................... 10-7
10.4.3 Internal Auto-Calibration (INT CAL) ................................................................................ 10-15
10.5 Calibration Errors ....................................................................................................................... 10-20
10.6 Calibration Data Reference ........................................................................................................ 10-21
10.6.1 Queries for External Calibration ........................................................................................10-21
10.6.2 Queries for Internal Calibration ......................................................................................... 10-24
10.6.3 CAL Item List .................................................................................................................... 10-25
11. SPECIFICATIONS ........................................................................................................... 11-1
11.1 Measurement Functions ............................................................................................................. 11-1
11.1.1 DC Voltage Measurement (DCV) ...................................................................................... 11-1
11.1.2 Resistance Measurement (2 WΩ/4 WΩ) ............................................................................ 11-4
11.1.3 DC Current Measurement (DCI) ........................................................................................ 11-8
11.1.4 AC Voltage Measurement (ACV) (7482 Only) ................................................................. 11-10
11.1.5 AC Current Measurement (ACI) (7482 Only) ................................................................... 11-13
11.1.6 Frequency/Period (FREQ/PERIOD) (7482 Only) ............................................................. 11-15
11.1.7 Ratio Measurement ............................................................................................................ 11-16
11.2 Integration Time ......................................................................................................................... 11-17
11.3 Input Terminals .......................................................................................................................... 11-17
11.4 NULL Function .......................................................................................................................... 11-17
11.5 Calculation Function .................................................................................................................. 11-18
11.5.1 Digital Filter ....................................................................................................................... 11-18
11.5.2 Format Calculations ........................................................................................................... 11-18
11.5.3 Comparator ......................................................................................................................... 11-19
11.5.4 Statistical Calculation ........................................................................................................ 11-20
11.6 Memory Function ....................................................................................................................... 11-20
11.7 Trigger Function ........................................................................................................................ 11-20
11.8 Remote Control .......................................................................................................................... 11-21
11.8.1 GPIB Interface ................................................................................................................... 11-21
11.8.2 USB Interface ..................................................................................................................... 11-21
11.8.3 LAN Interface 7481+06/7482+06 (Factory Option) .......................................................... 11-21
11.9 Control Signal ............................................................................................................................ 11-22
11.10 General Specifications ............................................................................................................... 11-22
APPENDIX .......................................................................................................................................... A-1
A.1 Error Message List .................................................................................................................... A-1
A.2 MENU Key Hierarchy .............................................................................................................. A-3
DIMENSIONAL OUTLINE DRAWING .................................................................................. EXT-1

No. Title Page
7481/7482 Digital Multimeter Operation Manual
LIST OF ILLUSTRATIONS
F-1
1-1 Operating Environment ..................................................................................................... 1-4
2-1 Front Panel ........................................................................................................................ 2-1
2-2 Rear Panel ......................................................................................................................... 2-6
5-1 Internal Circuit of Comparator Output ............................................................................. 5-20
6-1 Folder Hierarchy ............................................................................................................... 6-18
7-1 Trigger System Model Diagram (for SCPI Commands) .................................................. 7-2
7-2 External Trigger Signal and EXTernal Event Detection Position .................................... 7-13
7-3 Signal to Be Measured and LEVel Event Detection Position .......................................... 7-13
7-4 AC Power Waveform and LINE Event Detection Position .............................................. 7-14
7-5 Complete Signal Waveform .............................................................................................. 7-18
7-6 Trigger System Flowchart in FAST Mode ....................................................................... 7-22
7-7 Complete Signals in FAST Mode ..................................................................................... 7-25
8-1 REAL 64 Output Format .................................................................................................. 8-20
8-2 SCPI Status Register Configuration ................................................................................. 8-22
8-3 Event Register and Enable Register .................................................................................. 8-23
8-4 RQS/MSS Bit and Service Request (SRQ) ....................................................................... 8-26

No. Title Page
7481/7482 Digital Multimeter Operation Manual
LIST OF TABLES
T-1
1-1 Standard Accessory List ................................................................................................... 1-2
1-2 Optional Accessory List ....................................................................................................1-2
1-3 Power Supply Conditions ................................................................................................. 1-5
1-4 Power Plug for Each Country ........................................................................................... 1-7
1-5 Life Limited Parts ............................................................................................................. 1-13
1-6 Substances and Components to Be Sorted ........................................................................ 1-14
3-1 Initial States of Parameters ...............................................................................................3-2
3-2 Range Configuration (DCV) ............................................................................................. 3-7
3-3 Maximum Allowable Input Voltage (DCV) ..................................................................... 3-7
3-4 Maximum Allowable Input Voltage for Ratio Measurement ........................................... 3-9
3-5 Range Configuration (Resistance Measurement) ............................................................. 3-12
3-6 Maximum Allowable Input Voltage (Resistance Measurement) ..................................... 3-12
3-7 Range Configuration (DCI) .............................................................................................. 3-21
3-8 Range Configuration (ACV) ............................................................................................. 3-23
3-9 Maximum Allowable Input Voltage (ACV) ..................................................................... 3-23
3-10 Frequency Band and Response Time ................................................................................ 3-25
3-11 Range Configuration (ACI) .............................................................................................. 3-28
3-12 Frequency Band and Response Time ................................................................................ 3-29
3-13 Maximum Number of Display Digits by Gate Time ........................................................ 3-34
3-14 Frequency/Period Measurement Range ............................................................................ 3-38
3-15 Auto-Range Level ............................................................................................................. 3-40
3-16 Integration Time and Display Digits ................................................................................ 3-45
4-1 Key Functions ................................................................................................................... 4-2
4-2 Menu List .......................................................................................................................... 4-3
6-1 Memory Contents of Setting Conditions .......................................................................... 6-2
6-2 Format (ASCII) for Remote Output .................................................................................. 6-16
7-1 Event Source ..................................................................................................................... 7-12
7-2 Rate Time .......................................................................................................................... 7-21
8-1 Interface Setting Items and Factory Defaults ................................................................... 8-1
8-2 Interface Function ............................................................................................................. 8-2
8-3 Standard Bus Cable ........................................................................................................... 8-3
8-4 LAN Setting Items ............................................................................................................ 8-9
8-5 Communication Settings when Using LAN ..................................................................... 8-10
8-6 Output Data Element ........................................................................................................8-14
8-7 Mantissa Part and Exponent Part ...................................................................................... 8-16
8-8 Mantissa Part and Exponent Part (Frequency/Period) ...................................................... 8-17
8-9 Status Byte Register .......................................................................................................... 8-24
8-10 Standard Event Status Register ......................................................................................... 8-27
8-11 Measurement Event Register ............................................................................................ 8-28
8-12 Questionable Event Register ............................................................................................. 8-29
8-13 Operation Event Register ..................................................................................................8-30

No. Title Page
7481/7482 Digital Multimeter Operation Manual
LIST OF TABLES
T-2
A-1 Error Message List ............................................................................................................ A-1

7481/7482 Digital Multimeter Operation Manual
1. PREFACE
1-1
1. PREFACE
1.1 Product Overview
The 7481 is a digital multimeter capable of measuring DC voltage, DC current, and resistance, while the 7482
is a digital multimeter capable of measuring AC voltage (true RMS value), AC current, frequency, and period
in addition to DC voltage, DC current, and resistance.
The 7481/7481 is equipped with unique A/D conversion technology, allowing measurements with a high
resolution of 10 nV for DC voltage, 1  for resistance, and 100 fA for current, and a high accuracy of 5
ppm per year (relative accuracy of voltage measurement).
Also, the built-in self-calibration function makes it possible to perform high-accuracy measurement at any
time and even perform external calibration with a small number of standards.
The 7481/7482 is equipped with GPIB and USB as standard interfaces for automation systems, and is
designed with rear input terminals for system integration.
[Features]
• High-precision DC voltage or resistance measurement at 8½-digit display (maximum display: 119 999
999) with 0.01 ppm resolution
• High-precision DC current measurement at 7½-digit display with 0.1 ppm resolution
• Noise-resistant measurement with changeable integration time setting
• Data memory function (maximum 50,000 data or 500,000 data for the Option +06), pre-trigger
function
• NULL function to compensate offset
• Digital smoothing function
• Easy calibration
• GPIB interface, USB interface, trigger input, and measurement end signal output as standard
• Various calculation function such as dB, dBm, RMS, statistical processing and wire resistance value
temperature compensation (20 C)
• LAN interface (for the Option +06)

7481/7482 Digital Multimeter Operation Manual
1.2 Supplied Accessories
1-2
1.2 Supplied Accessories
The 7481/7482 standard accessories are listed below. If any accessory is missing or damaged, contact an
ADC CORPORATION sales representative. Specify the part number when ordering.
1.3 Optional Accessories
The 7481/7482 optional accessories are listed below. Specify the part number when ordering.
Table 1-1 Standard Accessory List
Name Part number Quantity
Power cable A01402 1
Input cable (test probe 1 m) CC010001 1
Alligator clip adapter for CC010001 CC015001 1
Current terminal protection fuse DFS-AN1R25A-1 1
Power fuse DFT-AA1A-1 1
EMI clamp DEE-100345-1 1
Quick Manual E7481/7482 (Q) 1
Table 1-2 Optional Accessory List
Name Part number
Input cable (for 4-wire measurement, with guard) A01005
Input cable (for 4-wire measurement) A01006
Input cable (banana-alligator) A01035
Input cable (test probe 1 m) CC010001
Alligator clip adapter for CC010001 CC015001
Front handle set 2U CC028002
Rack mount set 2U EIA CC024002
Rack mount set 2U JIS CC022002
(The front handle set and the rack mount set can be used in combination.)