HP 34401A User manual

HP 34401A
Multimeter
User’s Guide
Part Number 34401-90004
February 1996
For Safety information, Warranties, and Regulatory information,
see the pages behind the Index.
©Copyright Hewlett-Packard Company 1991, 1996
All Rights Reserved.

The HP 34401A is a 61⁄2-digit, high-performance digital multimeter.
Its combination of bench-top and system features makes this multimeter
a versatile solution for your measurement needs now and in the future.
Convenient Bench-Top Features
•Highly visible vacuum-fluorescent display
•Built-in math operations
•Continuity and diode test functions
•Hands-free, Reading Hold feature
•Portable, ruggedized case with non-skid feet
Flexible System Features
•HP-IB (IEEE-488) interface and RS-232 interface
•Standard programming languages: SCPI, HP 3478A, and Fluke 8840
•Reading rates up to 1000 readings per second
•Storage for up to 512 readings
•Limit testing with pass/fail signals
•Optional HP 34812A BenchLink/Meter Software
for Microsoft®WindowsTM
HP 34401A
Multimeter
Note: Unless otherwise indicated, this manual applies to all Serial Numbers.

The Front Panel at a Glance
1Measurement Function keys
2Math Operation keys
3Single Trigger / Autotrigger / Reading Hold key
4Shift / Local key
5Front / Rear Input Terminal Switch
6Range / Number of Digits Displayed keys
7Menu Operation keys
2

The Front-Panel Menu at a Glance
A: MEASurement MENU
1: AC FILTER

2: CONTINUITY

3: INPUT R

4: RATIO FUNC

5: RESOLUTION
F: CALibration MENU*
1: SECURED

[ 1: UNSECURED ]

[ 2: CALIBRATE ]

3: CAL COUNT

4: MESSAGE
*The commands enclosed in square brackets ( [ ] ) are “hidden” unless the multimeter
is UNSECURED for calibration.
B: MATH MENU
1: MIN-MAX

2: NULL VALUE

3: dB REL

4: dBm REF R

5: LIMIT TEST

6: HIGH LIMIT

7: LOW LIMIT
C: TRIGger MENU
1: READ HOLD

2: TRIG DELAY

3: N SAMPLES
D: SYStem MENU
1: RDGS STORE

2: SAVED RDGS

3: ERROR

4: TEST

5: DISPLAY

6: BEEP

7: COMMA

8: REVISION
E: Input / Output MENU
1: HP-IB ADDR

2: INTERFACE

3: BAUD RATE

4: PARITY

5: LANGUAGE
The menu is organized in a top-down tree structure with three levels.
3

Display Annunciators
*
Adrs
Rmt
Man
Trig
Hold
Mem
Ratio
Math
ERROR
Rear
Shift
4W
Turns on during a measurement.
Multimeter is addressed to listen or talk over the HP-IB interface.
Multimeter is in remote mode (remote interface).
Multimeter is using manual ranging (autorange is disabled).
Multimeter is waiting for a single trigger or external trigger.
Reading Hold is enabled.
Turns on when reading memory is enabled.
Multimeter is in dcv:dcv ratio function.
A math operation is enabled (null, min-max, dB, dBm, or limit test).
Hardware or remote interface command errors are detected.
Rear input terminals are selected.
“Shift” key has been pressed.
Press “Shift” again to turn off.
Multimeter is in 4-wire ohms function.
Multimeter is in continuity test function.
Multimeter is in diode test function.
To review the display annunciators, hold down the Shift key as you
turn on the multimeter.
4

The Rear Panel at a Glance
1Chassis Ground
2Power-Line Fuse-Holder Assembly
3Power-Line Voltage Setting
4Front and Rear Current Input Fuse
5Voltmeter Complete Output Terminal
6External Trigger Input Terminal
7HP-IB (IEEE-488) Interface connector
8RS-232 interface connector
Use the front-panel Input / Output Menu to:
•Select the HP-IB or RS-232 interface (see chapter 4).
•Set the HP-IB bus address (see chapter 4).
• Set the RS-232 baud rate and parity (see chapter 4).
5

In This Book
Quick Start Chapter 1 prepares the multimeter for use and helps you
get familiar with a few of its front-panel features.
Front-Panel Menu Operation Chapter 2 introduces you to the
front-panel menu and describes some of the multimeter’s menu features.
Features and Functions Chapter 3 gives a detailed description of the
multimeter’s capabilities and operation. You will find this chapter
useful whether you are operating the multimeter from the front panel or
over the remote interface.
Remote Interface Reference Chapter 4 contains reference
information to help you program the multimeter over the remote interface.
Error Messages Chapter 5 lists the error messages that may appear
as you are working with the multimeter. Each listing contains enough
information to help you diagnose and solve the problem.
Application Programs Chapter 6 contains several remote interface
application programs to help you develop programs for your
measurement application.
Measurement Tutorial Chapter 7 discusses measurement
considerations and techniques to help you obtain the best accuracies
and reduce sources of measurement error.
Specifications Chapter 8 lists the multimeter’s specifications and
describes how to interpret these specifications.
If you have questions relating to the operation of the HP 34401A,
call 1-800-452-4844 in the United States, or contact your nearest
Hewlett-Packard Sales Office.
If your HP 34401A fails within three years of purchase, HP will repair
or replace it free of charge. Call 1-800-258-5165 (“Express Exchange”)
in the United States, or contact your nearest Hewlett-Packard Sales Office.
6

Contents
Chapter 1 Quick Start
To Prepare the Multimeter for Use 13
If the Multimeter Does Not Turn On 14
To Adjust the Carrying Handle 16
To Measure Voltage 17
To Measure Resistance 17
To Measure Current 18
To Measure Frequency (or Period) 18
To Test Continuity 19
To Check Diodes 19
To Select a Range 20
To Set the Resolution 21
Front-Panel Display Formats 22
To Rack Mount the Multimeter 23
Chapter 2 Front-Panel Menu Operation
Front-Panel Menu Reference 27
A Front-Panel Menu Tutorial 29
To Turn Off the Comma Separator 37
To Make Null (Relative) Measurements 38
To Store Minimum and Maximum Readings 39
To Make dB Measurements 40
To Make dBm Measurements 41
To Trigger the Multimeter 42
To Use Reading Hold 43
To Make dcv:dcv Ratio Measurements 44
To Use Reading Memory 46
Chapter 3 Features and Functions
Measurement Configuration
AC Signal Filter 51
Continuity Threshold Resistance 52
DC Input Resistance 53
Resolution 54
Integration Time 57
Front / Rear Input Terminal Switching 58
Autozero 59
Ranging 60
Contents
7

Chapter 3 Features and Functions (continued)
Math Operations
Min-Max Operation 64
Null (Relative) Operation 65
dB Measurements 67
dBm Measurements 68
Limit Testing 69
Triggering
Trigger Source Choices 73
The Wait-for-Trigger State 76
Halting a Measurement in Progress 76
Number of Samples 77
Number of Triggers 78
Trigger Delay 79
Automatic Trigger Delays 81
Reading Hold 82
Voltmeter Complete Terminal 83
External Trigger Terminal 83
System-Related Operations
Reading Memory 84
Error Conditions 85
Self-Test 86
Display Control 87
Beeper Control 88
Comma Separators 89
Firmware Revision Query 89
SCPI Language Version Query 90
Remote Interface Configuration
HP-IB Address 91
Remote Interface Selection 92
Baud Rate Selection (RS-232) 93
Parity Selection (RS-232) 93
Programming Language Selection 94
Calibration
Calibration Security 95
Calibration Count 98
Calibration Message 99
Operator Maintenance
To Replace the Power-Line Fuse 100
To Replace the Current Input Fuses 100
Power-On and Reset State 101
Contents
Contents
8

Chapter 4 Remote Interface Reference
Command Summary 105
Simplified Programming Overview 112
The MEASure? and CONFigure Commands 117
Measurement Configuration Commands 121
Math Operation Commands 124
Triggering 127
Triggering Commands 130
System-Related Commands 132
The SCPI Status Model 134
Status Reporting Commands 144
Calibration Commands 146
RS-232 Interface Configuration 148
RS-232 Interface Commands 153
An Introduction to the SCPI Language 154
Output Data Formats 159
Using Device Clear to Halt Measurements 160
TALK ONLY for Printers 160
To Set the HP-IB Address 161
To Select the Remote Interface 162
To Set the Baud Rate 163
To Set the Parity 164
To Select the Programming Language 165
Alternate Programming Language Compatibility 166
SCPI Compliance Information 168
IEEE-488 Compliance Information 169
Chapter 5 Error Messages
Execution Errors 173
Self-Test Errors 179
Calibration Errors 180
Chapter 6 Application Programs
Using MEASure? for a Single Measurement 185
Using CONFigure with a Math Operation 186
Using the Status Registers 188
RS-232 Operation Using QuickBASIC 192
RS-232 Operation Using Turbo C 193
Contents
Contents
9

Chapter 7 Measurement Tutorial
Thermal EMF Errors 199
Loading Errors (dc volts) 199
Leakage Current Errors 199
Rejecting Power-Line Noise Voltages 200
Common Mode Rejection (CMR) 201
Noise Caused by Magnetic Loops 201
Noise Caused by Ground Loops 202
Resistance Measurements 203
4-Wire Ohms Measurements 203
Removing Test Lead Resistance Errors 204
Power Dissipation Effects 204
Settling Time Effects 204
Errors in High Resistance Measurements 205
DC Current Measurement Errors 205
True RMS AC Measurements 206
Crest Factor Errors 207
Loading Errors (ac volts) 209
Measurements Below Full Scale 210
High-Voltage Self-Heating Errors 210
Temperature Coefficient and Overload Errors 210
Low-Level Measurement Errors 211
Common Mode Errors 212
AC Current Measurement Errors 212
Frequency and Period Measurement Errors 213
Making High-Speed DC and Resistance Measurements 213
Making High-Speed AC Measurements 214
Chapter 8 Specifications
DC Characteristics 216
AC Characteristics 218
Frequency and Period Characteristics 220
General Information 222
Product Dimensions 223
To Calculate Total Measurement Error 224
Interpreting Multimeter Specifications 226
Configuring for Highest Accuracy Measurements 229
Index 231
Declaration of Conformity 237
Contents
Contents
10

1
Quick Start
1

Quick Start
One of the first things you will want to do with your multimeter is to
become acquainted with its front panel. We have written the exercises
in this chapter to prepare the multimeter for use and help you get
familiar with some of its front-panel operations.
The front panel has two rows of keys to select various functions and
operations. Most keys have a shifted function printed in blue above
the key. To perform a shifted function, press Shift (the Shift
annunciator will turn on). Then, press the key that has the desired
label above it. For example, to select the dc current function,
press Shift DC V .
If you accidentally press Shift , just press it again to turn off the
Shift annunciator.
The rear cover of this book is a fold-out Quick Reference Guide. On this
cover you will find a quick summary of various multimeter features.
12

To Prepare the Multimeter for Use
The following steps help you verify that the multimeter is ready for use.
1 Check the list of supplied items.
Verify that you have received the following items with your multimeter.
If anything is missing, contact your nearest Hewlett-Packard Sales Office.
One test lead kit.
One power cord.
This User’s Guide.
One Service Guide.
One folded Quick Reference card.
Certificate of Calibration.
2 Connect the power cord and turn on the multimeter.
The front-panel display will light up while the multimeter performs its
power-on self-test. The HP-IB bus address is displayed. Notice that the
multimeter powers up in the dc voltage function with autoranging enabled.
To review the power-on display with all annunciators turned on,
hold down Shift as you turn on the multimeter.
3Performacomplete self-test.
The complete self-test performs a more extensive series of tests than
those performed at power-on. Hold down Shift as you press the
Power switch to turn on the multimeter; hold down the key for more
than 5 seconds. The self-test will begin when you release the key.
If the self-test is successful, “PASS” is displayed. If the self-test is
not successful, “FAIL” is displayed and the ERROR annunciator turns
on. See the Service Guide for instructions on returning the multimeter
to Hewlett-Packard for service.
1
Chapter 1 Quick Start
To Prepare the Multimeter for Use
13

If the Multimeter Does Not Turn On
Use the following steps to help solve problems you might encounter
when turning on the multimeter. If you need more help, see the
Service Guide for instructions on returning the multimeter to
Hewlett-Packard for service.
1 Verify that there is ac power to the multimeter.
First, verify that the multimeter’s Power switch is in the “On” position.
Also, make sure that the power cord is firmly plugged into the power
module on the rear panel. You should also make sure that the power
source you plugged the multimeter into is energized.
2 Verify the power-line voltage setting.
The line voltage is set to the proper value for your country when the
multimeter is shipped from the factory. Change the voltage setting if
it is not correct. The settings are: 100, 120, 220, or 240 Vac (for 230 Vac
operation, use the 220 Vac setting).
See the next page if you need to change the line-voltage setting.
3 Verify that the power-line fuse is good.
The multimeter is shipped from the factory with a power-line fuse
installed. If you determine that the fuse is faulty, replace it with one
that has the same rating as indicated on the multimeter’s rear panel.
See the next page if you need to replace the power-line fuse.
To replace the 250 mAT fuse, order HP part number 2110-0817.
To replace the 125 mAT fuse, order HP part number 2110-0894.
Chapter 1 Quick Start
If the Multimeter Does Not Turn On
14

See rear panel for proper fuse rating .
HP Part Number: 2110-0817 (250 mAT)
2110-0894 (125 mAT)
100, 120, 220 (230) or 240 Vac
1 Remove the power cord. Remove the
fuse-holder assembly from the rear panel.
2 Remove the line-voltage selector from
the assembly.
3 Rotate the line-voltage selector until the
correct voltage appears in the window.
4 Replace the fuse-holder assembly in
the rear panel.
Verify that the correct line voltage is selected and the power-line fuse is good.
1
Chapter 1 Quick Start
If the Multimeter Does Not Turn On
15

To Adjust the Carrying Handle
To adjust the position, grasp the handle by the sides and pull outward.
Then, rotate the handle to the desired position.
Bench-top viewing positions Carrying position
Chapter 1 Quick Start
To Adjust the Carrying Handle
16

To Measure Voltage
Ranges: 100 mV, 1 V, 10 V, 100 V, 1000 V (750 Vac)
Maximum resolution: 100 nV (on 100 mV range)
AC technique: true RMS, ac-coupled
To Measure Resistance
Ranges: 100 Ω, 1 kΩ, 10 kΩ, 100 kΩ, 1 MΩ, 10 MΩ, 100 MΩ
Maximum resolution: 100 µΩ (on 100 ohm range)
1
Chapter 1 Quick Start
To Measure Voltage
17

To Measure Current
Ranges: 10 mA (dc only), 100 mA (dc only), 1 A , 3 A
Maximum resolution: 10 nA (on 10 mA range)
AC technique: true RMS, ac-coupled
To Measure Frequency (or Period)
Measurement band: 3 Hz to 300 kHz (0.33 sec to 3.3 µsec)
Input signal range: 100 mVac to 750 Vac
Technique: reciprocal counting
Chapter 1 Quick Start
To Measure Current
18

To Test Continuity
Test current source: 1 mA
Maximum resolution: 0.1 Ω(range is fixed at 1 kohm)
Beeper threshold: 1 Ω to 1000 Ω (beeps below adjustable threshold)
To Check Diodes
Test current source: 1 mA
Maximum resolution: 100 µV (range is fixed at 1 Vdc)
Beeper threshold: 0.3 volts ≤Vmeasured ≤0.8 volts (not adjustable)
1
Chapter 1 Quick Start
To Test Continuity
19