Agilent 34401A Multimeter Uncompromising Performance for Benchtop and System Testing

Product Overview

Measure up to 1000 volts with 6 1/2 digits resolution 0.0015% basic dcV accuracy (24 hour) 0.06% basic acV accuracy (1 year) 3 Hz to 300 kHz ac bandwidth 1000 readings/s direct to GPIB Superior Performance The Agilent Technologies 34401A multimeter gives you the performance you need for fast, accurate bench and system testing. The 34401A provides a combination of resolution, accuracy and speed that rivals DMMs costing many times more. 61/2 digits of resolution, 0.0015% basic 24-hr dcV accuracy and 1,000 readings/s direct to GPIB assure you of results that are accurate, fast, and repeatable. Use It on Your Benchtop The 34401A was designed with your bench needs in mind. Functions commonly associated with bench operation, like continuity and diode test, are built in. A Null feature allows you to remove lead resistance and other fixed offsets in your measurements. Other capabilities like min/max/avg
readouts and direct dB and dBm measurements make checkout with the 34401A faster and easier. The 34401A gives you the ability to store up to 512 readings in internal memory. For trouble-shooting, a reading hold feature lets you concentrate on placing your test leads without having to constantly glance at the display. Use It for Systems Testing For systems use, the 34401A gives you faster bus throughput than any other DMM in its class. The 34401A can send up to 1,000 readings/s directly across GPIB in user-friendly ASCII format. You also get both GPIB and RS-232 interfaces as standard features. Voltmeter Complete and External Trigger signals are provided so you can synchronize to other instruments in your test system. In addition, a TTL output indicates Pass/Fail results when limit testing is used. To ensure both forward and backward compatibility, the 34401A includes three command languages (SCPI, Agilent 3478A and Fluke 8840A /42A), so you dont have to rewrite your existing test software. An optional rack mount kit is available.
Easy to Use Commonly accessed attributes, such as functions, ranges, and resolution are selected with a single button press. Advanced features are available using menu functions that let you optimize the 34401A for your applications. The included Agilent IntuiLink software allows you to put your captured data to work easily, using PC applications such as Microsoft Excel or Word to analyze, interpret, display, print, and document the data you get from the 34401A. You can specify the meter setup and take a single reading or log data to the Excel spreadsheet in specified time intervals. Programmers can use ActiveX components to control the DMM using SCPI commands. To find out more about IntuiLink, visit www.agilent.com/find/intuilink 1-Year Warranty With your 34401A, you get full documentation, a high-quality test lead set, calibration certificate with test data, and a 1-year warranty, all for one low price.
Accuracy Specifications (% of reading + % of range)1
Function Range 3 Frequency, etc. 24 Hour 2 23C 1C 0.0030 + 0.0030 0.0020 + 0.0006 0.0015 + 0.0004 0.0020 + 0.0006 0.0020 + 0.Hz 5 Hz 5 Hz 10 Hz 10 Hz 20 kHz 20 kHz 50 kHz 50 kHz 100 kHz 100 kHz 300 kHzHz 5 Hz 5 Hz 10 Hz 10 Hz 20 kHz 20 kHz 50 kHz 50 kHz 100 kHz kHz 300 kHz 6 1.00 + 0.03 0.35 + 0.03 0.04 + 0.03 0.10 + 0.05 0.55 + 0.08 4.00 + 0.50 1.00 + 0.02 0.35 + 0.02 0.04 + 0.02 0.10 + 0.04 0.55 + 0.08 4.00 + 0.Day 23C 5C 0.0040 + 0.0035 0.0030 + 0.0007 0.0020 + 0.0005 0.0035 + 0.0006 0.0035 + 0.0010 1.00 + 0.04 0.35 + 0.04 0.05 + 0.04 0.11 + 0.05 0.60 + 0.08 4.00 + 0.50 1.00 + 0.03 0.35 + 0.03 0.05 + 0.03 0.11 + 0.05 0.60 + 0.08 4.00 + 0.50 0.008 + 0.004 0.008 + 0.001 0.008 + 0.001 0.008 + 0.001 0.008 + 0.001 0.020 + 0.001 0.800 + 0.010 0.030 + 0.020 0.030 + 0.005 0.080 + 0.010 0.120 + 0.020 1.00 + 0.04 0.30 + 0.04 0.10 + 0.04 1.10 + 0.06 0.35 + 0.06 0.15 + 0.06 0.10 0.05 0.03 0.01 0.008 + 0.030 0.008 + 0.Year 23C 5C 0.0050 + 0.0035 0.0040 + 0.0007 0.0035 + 0.0005 0.0045 + 0.0006 0.0045 + 0.0010 1.00 + 0.04 0.35 + 0.04 0.06 + 0.04 0.12 + 0.04 0.60 + 0.08 4.00 + 0.50 1.00 + 0.03 0.35 + 0.03 0.06 + 0.03 0.12 + 0.04 0.60 + 0.08 4.00 + 0.50 0.010 + 0.004 0.010 + 0.001 0.010 + 0.001 0.010 + 0.001 0.010 + 0.001 0.040 + 0.001 0.800 + 0.010 0.050 + 0.020 0.050 + 0.005 0.100 + 0.010 0.120 + 0.020 1.00 + 0.04 0.30 + 0.04 0.10 + 0.04 1.10 + 0.06 0.35 + 0.06 0.15 + 0.06 0.10 0.05 0.03 0.01 0.010 + 0.030 0.010 + 0.020 Temperature Coefficient 0C to -18C 28C to -55C 0.0005 + 0.0005 0.0005 + 0.0001 0.0005 + 0.0001 0.0005 + 0.0001 0.0005 + 0.0001 0.100 + 0.004 0.035 + 0.004 0.005 + 0.004 0.011 + 0.005 0.060 + 0.008 0.20 + 0.02 0.100 + 0.003 0.035 + 0.003 0.005 + 0.003 0.011 + 0.005 0.060 + 0.008 0.20 + 0.02 0.0006 + 0.0005 0.0006 + 0.0001 0.0006 + 0.0001 0.0006 + 0.0001 0.0010 + 0.0002 0.0030 + 0.0004 0.1500 + 0.0002 0.0020 + 0.0020 0.0020 + 0.0005 0.0050 + 0.0010 0.005 + 0.0020 0.100 + 0.006 0.035 + 0.006 0.015 + 0.006 0.100 + 0.006 0.035 + 0.006 0.015 + 0.006 0.005 0.005 0.001 0.001 0.001 + 0.002 0.001 + 0.002

DC voltage

100.0000 mV 1.000000 V 10.00000 V 100.0000 V 1000.000 V 100.0000 mV

True rms AC voltage4

1.000000 V to 750.000 V

Resistance 7

100.0000 1.000000 k 10.00000 k 100.0000 k 1.000000 M 10.00000 M 100.0000 M 10.00000 mA 100.0000 mA 1.000000 A 3.00000 A 1.000000 A
1 mA Current Source 0.0030 + 0.mA 0.0020 + 0.A 0.0020 + 0.A 0.0020 + 0.0005 5.0 A 0.002 + 0.nA 0.015 + 0.nA || 10 M 0.300 + 0.010 < 0.1 V Burden Voltage < 0.6 V < 1.0 V < 2.0 V 3 Hz 5 Hz 5 Hz 10 Hz 10 Hz 5 kHz 3 Hz 5 Hz 5 Hz 10 Hz 10 Hz 5 kHz 3 Hz 5 Hz 5 Hz 10 Hz 10 Hz 40 Hz 40 Hz 300 kHz 1 mA test current 1 mA test current 0.005 + 0.010 0.010 + 0.004 0.050 + 0.006 0.100 + 0.020 1.00 + 0.04 0.30 + 0.04 0.10 + 0.04 1.10 + 0.06 0.35 + 0.06 0.15 + 0.06 0.10 0.05 0.03 0.006 0.002 + 0.030 0.002 + 0.010

DC current

True rms AC current 4

3.00000 A

Frequency or period 8

100 mV to 750 V

Continuity Diode test

1000.0 1.0000 V

Specifications are for 1 hr warm-up and digits, slow ac filter. Relative to calibration standards. 20% over range on all ranges except 1000 Vdc and 750 Vac ranges. For sinewave input > 5% of range. For inputs from 1% to 5% of range and < 50 kHz, add 0.1% of range additional error. 750 V range limited to 100 kHz or 8 x 107 Volt-Hz. Typically 30% of reading error at 1 MHz. Specifications are for 4-wire ohms function or 2-wire ohms using Math Null. Without Math Null, add 0.2 additional error in 2-wire ohms function. Input >100 mV. For 10 mV to 100 mV inputs multiply % of reading error x10. Accuracy specifications are for the voltage measured at the input terminals only. 1 mA test current is typical. Variation in the current source will create some variation in the voltage drop across a diode junction.
103.6 mm 254.4 mm 374.0 mm
88.5 mm 212.6 mm 348.3 mm
Measurement Characteristics

DC Voltage

Measurement Method: Continuously integrating multi-slope III A-D converter A-D Linearity: 0.0002% of reading + 0.0001% of range Input Resistance: 10 M or 0.1 V, 1 V, 10 V ranges: Selectable > 10,000 M 100 V, 1000 V ranges: 10 M 1% Input Bias Current: < 30 pA at 25C Input Protection: 1000 V all ranges dcV:dcV ratio accuracy: V input Accuracy + Vrelevance Accuracy

True RMS AC Current

Measurement Method: Directly coupled to the fuse and shunt. ac coupled true rms measurement (measures the ac component only). Shunt Resistance: 0.1 for 1 A and 3 A ranges Input Protection: Externally accessible 3 A 250 V fuse Internal 7 A 250 V fuse

Triggering and Memory

Reading HOLD Sensitivity: 10%, 1%, 0.1%, or 0.01% of range Samples/Trigger: 1 to 50,000 Trigger Delay: 0 to 3600 s: 10 s step size External Trigger Delay: < 1 ms External Trigger Jitter: < 500 s Memory: 512 readings

Frequency and Period

Measurement Method: Reciprocal counting technique Voltage Ranges: Same as ac voltage function Gate Time: 1 s, 100 ms, or 10 ms

Math Functions

NULL, min/max/average, dBm, dB, limit test (with TTL output)

True RMS AC Voltage

Measurement Method: AC-coupled true rms-measures the ac component of the input with up to 400 Vdc of bias on any range. Crest Factor: Maximum of 5:1 at full scale. Additional Crest Factor errors (non-sinewave): Crest factor 1-2: 0.05% of reading Crest factor 2-3: 0.15% of reading Crest factor 3-4: 0.30% of reading Crest factor 4-5: 0.40% of reading Input Impedance: 1 M 2% in parallel with 100 pF Input Protection: 750 Vrms all ranges
Standard Programming Languages
SCPI (IEEE-488.2), Agilent 3478A, Fluke 8840A/42A

Continuity/Diode

Response Time: 300 samples/s with audible tone Continuity Threshold: Selectable from 1 to 1000

Accessories Included

Test lead kit with probe, alligator and grabber attachments Operating manual, service manual, test report and power cord
Measurement Noise Rejection 60 (50) Hz1
dc CMRR: 140 dB ac CMRR: 70 dB

General Specifications

Power Supply: 100 V/120 V/220 V/240 V 10% Power Line Frequency: 45 Hz to 66 Hz and 360 Hz to 440 Hz, Automatically sensed at power-on Power Consumption: 25 VA peak (10 W average) Operating Environment: Full accuracy for 0C to 55C, Full accuracy to 80% R.H. at 40C Storage Temperature: -40C to 70C Weight: 3.6 kg (8.0 lbs) Safety: Designed to CSA, UL-1244, IEC-348 RFI and ESD: MIL-461C, FTZ 1046, FCC Vibration & Shock: MIL-T-28800E, Type III, Class 5 (sine only) Warranty: 1 year
Integration Time and Normal Mode Rejection2
100 plc/1.67 s (2 s): 60 dBplc/167 ms (200 ms): 60 dBplc/16.7 ms (20 ms): 60 dB <1 plc/3 ms or 800 s): 0 dB

Resistance

Measurement Method: Selectable 4-wire or 2-wire Ohms. Current source referenced to LO input. Maximum Lead Resistance (4-wire): 10% of range per lead for 100 , 1 k ranges. 1 k per lead on all other ranges. Input Protection: 1000 V all ranges
Operating Characteristics 4
Function dcV, dcl, and Resistance Digits 6 1/1/1/1/1/1/1/1/1/1/1/1/2 Reading/s 0.6 (0.5) 6 (5) 60 (50) 0.15 slow (3 Hz) 1 medium (20 Hz) 10 fast (200 Hz) 9.8 80

DC Current

Shunt Resistance: 5 for 10 mA, 100 mA 0.1 for 1 A, 3 A Input Protection: Externally accessible 3 A 250 V fuse Internal 7 A 250 V fuse

acV, acl

Frequency or Period
Configuration rates: Autorange rate (dc Volts): ASCII readings to RS-232: ASCII readings to RS-232: Maximum internal trig rate: Max. ext trig. rate to memory: 26/s to 50/s >30/s 55/s 1000/s 1000/s 1000/s

For 1 k unbalanced in LO lead, 500 V peak maximum. For power line frequency 0.1%. For power line frequency 0.1% use 40 dB or 3% use 30 dB. Reading speeds for 60 Hz and (50 Hz) operation. Maximum useful limit with default settling delays defeated. Speeds are for 2 digits, delay 0, auto-zero and display OFF.

Ordering Information

Agilent 34401A multimeter accessories included: Test lead kit with probe, alligator, and grabber attachments, operating manual, service manual, calibration certificate, test report, and power cord. Options
34401A-1CM Rack mount kit* (P/N 5063-9240) 34401A-OBO DMM without manuals 34401A-A6J ANSI Z540 compliant calibration

Remove all doubt

Our repair and calibration services will get your equipment back to you, performing like new, when promised. You will get full value out of your Agilent equipment throughout its lifetime. Your equipment will be serviced by Agilent-trained technicians using the latest factory calibration procedures, automated repair diagnostics and genuine parts. You will always have the utmost confidence in your measurements. Agilent offers a wide range of additional expert test and measurement services for your equipment, including initial start-up assistance onsite education and training, as well as design, system integration, and project management. For more information on repair and calibration services, go to:
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For more information on Agilent Technologies products, applications or services, please contact your local Agilent office. The complete list is available at:
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Manual Options (Please specify one)
34401A-ABA 34401A-ABD 34401A-ABE 34401A-ABF 34401A-ABJ 34401A-ABZ 34401A-AB0 34401A-AB1 34401A-AB2 34401A-AKT US English German Spanish French Japanese Italian Taiwan Chinese Korean Chinese Russian

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Agilent Accessories

11059A 11060A 11062A 34131 34161A 34171B 34172B 34330A E2308A Kelvin probe set Surface mount device (SMD) test probes Kelvin clip set Hard transit case Accessory pouch Input terminal connector (sold in pairs) Input calibration short (sold in pairs) 30 A current shunt 5 k thermistor probe

Agilent Open

www.agilent.com/find/open Agilent Open simplifies the process of connecting and programming test systems to help engineers design, validate and manufacture electronic products. Agilent offers open connectivity for a broad range of system-ready instruments, open industry software, PC-standard I/O and global support, which are combined to more easily integrate test system development.
Ireland 204 Israel 972-3-9288-504/544 Italy 8484 Netherlands 31 (0) 2111 Spain 34 (91) Sweden 0200-55 Switzerland (French) 41 (21) 8113811(Opt 2) Switzerland (German) (Opt 1) United Kingdom 44 (0) Other European Countries: www.agilent.com/find/contactus
Revised: October 24, 2007
* For racking two side-by-side, order both items below: Lock link kit (P/N 5061-9694) Flange kit (P/N 5063-9212)
Product specifications and descriptions in this document subject to change without notice. Agilent Technologies, Inc. 2007 Printed in USA, December 20, 2007 5968-0162EN
www.lxistandard.org LXI is the LAN-based successor to GPIB, providing faster, more efficient connectivity. Agilent is a founding member of the LXI consortium.

Agilent 34401A 6 Digit Multimeter

Users Guide

Agilent Technologies

Notices

Agilent Technologies, Inc. 1991 - 2007 No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Technologies, Inc. as governed by United States and international copyright laws.

Warranty

The material contained in this document is provided as is, and is subject to being changed, without notice, in future editions. Further, to the maximum extent permitted by applicable law, Agilent disclaims all warranties, either express or implied, with regard to this manual and any information contained herein, including but not limited to the implied warranties of merchantability and fitness for a particular purpose. Agilent shall not be liable for errors or for incidental or consequential damages in connection with the furnishing, use, or performance of this document or of any information contained herein. Should Agilent and the user have a separate written agreement with warranty terms covering the material in this document that conflict with these terms, the warranty terms in the separate agreement shall control.

Safety Notices

CAU T ION
A CAUTION notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly performed or adhered to, could result in damage to the product or loss of important data. Do not proceed beyond a CAUTION notice until the indicated conditions are fully understood and met.

Manual Part Number

34401-90004

Edition

Seventh Edition. August 2007 Printed in Malaysia Agilent Technologies, Inc. 3501 Stevens Creek Blvd. Santa Clara, CA 95052 USA Microsoft and Windows are U.S. registered trademarks of Microsoft Corporation.

WARN IN G

A WARNING notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly performed or adhered to, could result in personal injury or death. Do not proceed beyond a WARNING notice until the indicated conditions are fully understood and met.

Software Revision

This guide is valid for the firmware that was installed in the instrument at the time of manufacture. However, upgrading the firmware may add or change product features. For the latest firmware and documentation, go to the product page at: www.agilent.com/find/34401A

Technology Licenses

The hardware and/or software described in this document are furnished under a license and may be used or copied only in accordance with the terms of such license.

Restricted Rights Legend

U.S. Government Restricted Rights. Software and technical data rights granted to the federal government include only those rights customarily provided to end user customers. Agilent provides this customary commercial license in Software and technical data pursuant to FAR 12.211 (Technical Data) and 12.212 (Computer Software) and, for the Department of Defense, DFARS 252.227-7015 (Technical Data - Commercial Items) and DFARS 227.7202-3 (Rights in Commercial Computer Software or Computer Software Documentation).

34401A Users Guide

Safety Information
General Do not use this product in any manner not specified by the manufacturer. The protective features of this product may be impaired if it is used in a manner not specified in the operation instructions. Do not install substitute parts or perform any unauthorized modification to the product. Return the product to an Agilent Technologies Sales and Service Office for service and repair to ensure that safety features are maintained. Ground the Instrument If your product is provided with a grounding-type power plug, the instrument chassis and cover must be connected to an electrical ground to minimize shock hazard. The ground pin must be firmly connected to an electrical ground (safety ground) terminal at the power outlet. Any interruption of the protective (grounding) conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury. Cleaning Clean the outside of the instrument with a soft, lint-free, slightly dampened cloth. Do not use detergent or chemical solvents.

To replace the 250 mAT fuse, order Agilent part number 2110-0817.
1 Remove the power cord. Remove the
fuse-holder assembly from the rear panel.
2 Remove the line-voltage selector from

the assembly.

See rear panel for proper fuse rating.
Agilent Part Number: 2110-0817 (250 mAT)
3 Rotate the line-voltage selector until the
correct voltage appears in the window.
4 Replace the fuse-holder assembly in

the rear panel.

100, 120, 220 (230) or 240 Vac
Verify that the correct line voltage is selected and the power-line fuse is good.
Chapter 1 Quick Start To Adjust the Carrying Handle
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 Measure Voltage

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 , 1 k, 10 k, 100 k, 1 M, 10 M, 100 M Maximum resolution: 100 (on 100 ohm range)
Chapter 1 Quick Start To Measure Current

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 sec) Input signal range: 100 mVac to 750 Vac Technique: reciprocal counting
Chapter 1 Quick Start To Test Continuity

To Test Continuity

Test current source: 1 mA Maximum resolution: 0.1 (range is fixed at 1 kohm) Beeper threshold: 1 to 1000 (beeps below adjustable threshold)

To Check Diodes

Test current source: 1 mA Maximum resolution: 100 V (range is fixed at 1 Vdc) Beeper threshold: 0.3 volts Vmeasured 0.8 volts (not adjustable)
Chapter 1 Quick Start To Select a Range

To Select a Range

You can let the multimeter automatically select the range using autoranging or you can select a fixed range using manual ranging.
Selects a lower range and disables autoranging.
Selects a higher range and disables autoranging.
Man annunciator is on when manual range is enabled.
Toggles between autoranging and manual ranging.
Autoranging is selected at power-on and after a remote interface reset. Autorange thresholds: Down range at <10% of range Up range at >120% of range If the input signal is greater than the present range can measure, the multimeter will give an overload indication (OVLD). For frequency and period measurements from the front panel, ranging applies to the signals input voltage, not its frequency. The range is fixed for continuity (1 k range) and diode (1 Vdc range).

2 Move down a level and then across to the RATIO FUNC command. 4: RATIO FUNC
3 Move down to the parameter level. For this command, there is only one choice on this level. DCV:DCV
4 Select the ratio function and turn off the menu. Notice that the Ratio annunciator turns on. CHANGE SAVED
To disable ratio measurements, select a different measurement function by pressing any front-panel function key.
Chapter 2 Front-Panel Menu Operation To Use Reading Memory

To Use Reading Memory

The multimeter can store up to 512 readings in internal memory. The following steps demonstrate how to store readings and retrieve them.
1 Select the function. Select any measurement function. You can also select Null, MinMax, dB, dBm, or limit test. You can change the function at any time during reading memory.

Single

2 Select the single trigger mode. Notice that the Trig annunciator turns on. When reading memory is enabled, readings are stored when you trigger the multimeter. For this example, single triggering is used to store readings. You can also use auto triggering or reading hold.
3 Turn on the menu. A: MEAS MENU
4 Move across to the SYS MENU choice on this level. D: SYS MENU
5 Move down to a level to the RDGS STORE command. 1: RDGS STORE
6 Move down a level and then across to the ON choice. ON
7 Save the change and exit the menu. Notice that the Mem (memory) annunciator turns on to indicate that the multimeter is ready to store readings. Up to 512 readings can be stored in first-in-first-out (FIFO) order. When memory is full, the Mem annunciator will turn off. Readings are preserved until you re-enable reading memory at another time, turn off the power, or perform a remote interface reset.

Single Single Single

8 Trigger the multimeter three times. This stores three readings in memory.
9 Use menu recall to retrieve the stored readings. This takes you to the SAVED RDGS command in the SYS MENU. 2: SAVED RDGS
10 Move down a level to view the first stored reading. Reading memory is automatically turned off when you go to the parameter level in the menu. The first reading displayed is the first reading that was stored (FIFO). If no readings are stored in memory, EMPTY is displayed. The stored readings are displayed with their units ( , m, k, etc.) when appropriate. For example:

Resolution Choices

Fast 4 Digit

Integration

0.02 PLC 1 PLC 0.2 PLC 10 PLC 10 PLC 100 PLC

* Slow 4 Digit

Fast 5 Digit
* Slow 5 Digit (default) * Fast 6 Digit

Slow 6 Digit

* These settings configure the multimeter just as if you had pressed the corresponding DIGITS keys from the front panel.
113.325,6 OHM This is the 100 ohm range, 612 digits are displayed.
The resolution is stored in volatile memory; the multimeter sets the resolution to 512 digits (for all functions) when power has been off or after a remote interface reset. The resolution is fixed at 512 digits for continuity and diode tests. For dc and resistance measurements, changing the number of digits does more than just change the resolution of the multimeter. It also changes the integration time, which is the period the multimeters analog-to-digital (A/D) converter samples the input signal for a measurement. See also Integration Time, on page 57. For ac measurements, the resolution is actually fixed at 612 digits. If you select 412 digits or 512 digits, the multimeter masks one or two digits. The only way to control the reading rate for ac measurements is by setting a trigger delay (see page 79). For ratio measurements, the specified resolution applies to the signal connected to the Input terminals.

Resolution (continued)

Front-Panel Operation: Select either the slow or fast mode for each resolution setting. The default mode is 5 digits slow. 5: RESOLUTION (MEAS MENU)
See also To Set the Resolution, on page 21.
Remote Interface Operation: You can set the resolution using the following commands. CONFigure:<function> {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF} MEASure:<function>? {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF} <function>:RESolution {<resolution>|MIN|MAX}
Specify the resolution in the same units as the measurement function, not in number of digits. For example, for dc volts, specify the resolution in volts. For frequency, specify the resolution in hertz. CONF:VOLT:DC 10,0.001 MEAS:CURR:AC? 1,1E-6 CONF:FREQ 1 KHZ,0.1 Hz VOLT:AC:RES 0.digits on the 10 Vdc range 612 digits on the 1 A range 1000 Hz input, 0.1 Hz resolution 50 mV resolution on the ac function

DC V Null Min-Max dB dBm Limit

X X X X X

2W X X

4W X X

From the front panel, you enable a math operation by pressing the appropriate key. The exception is Limit Test which you enable using the LIMIT TEST command in the MATH MENU. From the remote interface, the math operations and registers are controlled using commands within the CALCulate command subsystem. First, select the math operation you want to use (the default function is null): CALCulate:FUNCtion {NULL|DB|DBM|AVERage|LIMit} Then, enable the selected math function by turning the math state on: CALCulate:STATe ON

MinMax Operation

The min-max operation stores the minimum and maximum readings during a series of measurements. The multimeter then calculates the average of all readings and records the number of readings taken since min-max was enabled. Applies to all measurement functions, except continuity and diode.
After you enable min-max, the first reading that the multimeter takes is stored as both the minimum and maximum value. The minimum is replaced with any subsequent value that is less. The maximum is replaced with any subsequent value that is greater. The multimeter displays MIN or MAX and beeps (if the front-panel beeper is enabled) whenever a new minimum or maximum is found. It is possible that the multimeter will beep even if the displayed reading does not change; this is because the multimeters internal resolution may be greater than the displayed resolution. See also Beeper Control, on page 88. The minimum, maximum, average, and count are stored in volatile memory; the multimeter clears the values when min-max is turned on, when power has been off, or after a remote interface reset. Front-Panel Operation: After enabling min-max, you can read the stored minimum, maximum, average, and count by pressing Shift > (Menu Recall). Turning on the menu does not disable the min-max operation; the multimeter will resume taking measurements when you turn off the menu. 1: MIN-MAX (MATH MENU)
See also To Store Minimum and Maximum Readings, on page 39.
Remote Interface Operation: You can use the following commands to make min-max measurements. CALCulate:FUNCtion AVERage CALCulate:STATe {OFF|ON} CALCulate:AVERage:MINimum? CALCulate:AVERage:MAXimum? CALCulate:AVERage:AVERage? CALCulate:AVERage:COUNt?
read the minimum value read the maximum value read the average of all readings read the count
A new command is available starting with firmware Revision 2 which allows you to take readings using INITiate without storing them in internal memory. This command may be useful with the min-max operation since it allows you to determine the average of a series of readings without storing the individual values. DATA:FEED RDG_STORE, "" DATA:FEED RDG_STORE, "CALCulate" do not store readings store readings (default)

dB Measurements

Each dB measurement is the difference between the input signal and a stored relative value, with both values converted to dBm. dB = reading in dBm relative value in dBm Applies to dc voltage and ac voltage measurements only.
The relative value is adjustable and you can set it to any value between 0 dBm and 200.00 dBm. The relative value is stored in volatile memory; the value is cleared when power has been off, after a remote interface reset, or after a function change. The relative value is stored in the multimeters dB Relative Register. There are two ways you can specify the relative value. First, you can enter a specific number into the register from the front-panel menu or from the remote interface. Any previously stored value is replaced with the new value. If you are operating the multimeter from the front panel, entering a relative value also turns on the dB function. The second way to enter the relative value is to let the multimeter take the first reading, convert it to dBm, and store that value in the register. Changing the dBm reference resistance (see page 68) does not change the stored relative value. After you enable dB, the first reading taken will be 0 dB (if you have not changed the value stored in the register). If you entered a number into the register, as described in the paragraph above, the first reading does not overwrite the stored value.
Front-Panel Operation: After enabling dB, you can edit the stored relative value by pressing Shift > (Menu Recall). Any previously stored value is replaced with the new value. Turning on the menu does not disable the dB operation; the multimeter will resume taking measurements when you turn off the menu. 3: dB REL (MATH MENU)
See also To Make dB Measurements, on page 40.
Remote Interface Operation: You can use the following commands to make dB measurements. Math must be enabled before you can store a value to the Relative Register. CALCulate:FUNCtion DB CALCulate:STATe {OFF|ON} CALCulate:DB:REFerence {<value>|MINimum|MAXimum}

dBm Measurements

The dBm operation calculates the power delivered to a resistance referenced to 1 milliwatt. dBm = 10 Log10 ( reading2 / reference resistance / 1 mW ) Applies to dc voltage and ac voltage measurements only.
You can choose from 17 different reference resistance values. The factory setting for the reference resistance is 600. The choices are: 50, 75, 93, 110, 124, 125, 135, 150, 250, 300, 500, 600, 800, 900, 1000, 1200, or 8000 ohms.

See also To Set the Parity, on page 164.
Programming Language Selection
You can select one of three languages to program the multimeter from the selected remote interface. The language is SCPI when the multimeter is shipped from the factory.
Select one of the following: SCPI, Agilent 3478A, or Fluke 8840A. The language selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset. There are certain restrictions to be aware of when you are selecting the interface language (see also Remote Interface Selection, on page 92). The Agilent 3478A and Fluke 8840A/8842A languages are not supported on the RS-232 interface.
Front-Panel Operation: 5: LANGUAGE (I/O MENU)
See also To Select the Programming Language, on page 165.
Remote Interface Operation: L1 L2 L3 select SCPI language select Agilent 3478A language select Fluke 8840A language
Chapter 3 Features and Functions Calibration Overview

Calibration Overview

This section gives a brief introduction to the calibration features of the multimeter. For a more detailed discussion of the calibration procedures, see chapter 4 in the Service Guide.

Calibration Security

This feature allows you to enter a security code to prevent accidental or unauthorized calibrations of the multimeter. When you first receive your multimeter, it is secured. Before you can calibrate the multimeter, you must unsecure it by entering the correct security code.
The security code is set to HP034401 when the multimeter is shipped from the factory. The security code is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset. To secure the multimeter from the remote interface, the security code may contain up to 12 alphanumeric characters as shown below. The first character must be a letter, but the remaining characters can be letters or numbers. You do not have to use all 12 characters but the first character must always be a letter. A _ _ _ _ _ _ _ _ _ _ _ (12 characters)
To secure the multimeter from the remote interface so that it can be unsecured from the front panel, use the eight-character format shown below. The first two characters must be HP and the remaining characters must be numbers. Only the last six characters are recognized from the front panel, but all eight characters are required. (To unsecure the multimeter from the front panel, omit the HP and enter the remaining numbers as shown on the following pages.) H P _ _ _ _ _ _ (8 characters)
If you forget your security code, you can disable the security feature by adding a jumper inside the multimeter, and then entering a new code. See the Service Guide for more information.
Calibration Security (continued)

You can set the address to 31 which is the talk only mode. In this mode, the multimeter can output readings directly to a printer without being addressed by a bus controller (over either GPIB or RS-232). For proper operation, make sure your printer is configured in the listen always mode. Address 31 is not a valid address if you are operating the multimeter from the GPIB interface with a bus controller. If you select the RS-232 interface and then set the GPIB address to the talk only address (31), the multimeter will send readings over the RS-232 interface when in the local mode.
Chapter 4 Remote Interface Reference To Set the GPIB Address

To Set the GPIB Address

Each device on the GPIB (IEEE-488) interface must have a unique address. You can set the multimeters address to any value between 0 and 31. The address is set to 22 when the multimeter is shipped from the factory. The address is displayed on the front panel when you turn on the multimeter. See also GPIB Address, on page 91.
1 Turn on the front-panel menu. A: MEAS MENU
2 Move across to the I/O MENU choice on this level. E: I/O MENU
3 Move down a level to the HP-IB ADDR command. 1: HP-IB ADDR
4 Move down to the parameter level to set the address. Use the left/right and down/up arrow keys to change the address. 22 ADDR
5 Save the change and turn off the menu. The address is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.
Chapter 4 Remote Interface Reference To Select the Remote Interface
To Select the Remote Interface
The multimeter is shipped with both an GPIB (IEEE-488) interface and an RS-232 interface. Only one interface can be enabled at a time. The GPIB interface is selected when the multimeter is shipped from the factory. See also Remote Interface Selection, on page 92.
3 Move down a level and then across to the INTERFACE command. 2: INTERFACE
4 Move down to the parameter level to select the interface. Use the left/right arrow keys to see the interface choices. Choose from the following: HP-IB / 488 or RS-232. HP-IB / 488
5 Save the change and turn off the menu. The interface selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.
Chapter 4 Remote Interface Reference To Set the Baud Rate

To Set the Baud Rate

You can select one of six baud rates for RS-232 operation. The rate is set to 9600 baud when the multimeter is shipped from the factory. See also Baud Rate Selection, on page 93.
3 Move down a level and then across to the BAUD RATE command. 3: BAUD RATE
4 Move down to the parameter level to select the baud rate. Use the left/right arrow keys to see the baud rate choices. Choose from one of the following: 300, 600, 1200, 2400, 4800, or 9600 baud. 9600 BAUD
5 Save the change and exit the menu. The baud rate selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.

Chapter 4 Remote Interface Reference To Set the Parity

To Set the Parity

You can select the parity for RS-232 operation. The multimeter is configured for even parity with 7 data bits when shipped from the factory. See also Parity Selection, on page 93.
3 Move down a level and then across to the PARITY command. 4: PARITY
4 Move down to the parameter level to select the parity. Use the left/right arrow keys to see the parity choices. Choose from one of the following: None (8 data bits), Even (7 data bits), or Odd (7 data bits). When you set parity, you are indirectly setting the number of data bits. EVEN: 7 BITS
5 Save the change and turn off the menu. The parity selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.
Chapter 4 Remote Interface Reference To Select the Programming Language
To Select the Programming Language
You can select one of three languages to program the multimeter from the selected remote interface. The language is SCPI when the multimeter is shipped from the factory. See also Programming Language Selection, on page 94.
3 Move down a level and then across to the LANGUAGE command. 5: LANGUAGE
4 Move down to the parameter level to select the language. Choose from one of the following: SCPI, Agilent 3478A, or Fluke 8840A. SCPI
5 Save the change and turn off the menu. The language selection is stored in non-volatile memory, and does not change when power has been off or after a remote interface reset.
Chapter 4 Remote Interface Reference Alternate Programming Language Compatibility
Alternate Programming Language Compatibility
You can configure the Agilent 34401A to accept and execute the commands of either the Agilent 3478A multimeter or the Fluke 8840A/8842A multimeter. Remote operation will only allow you to access the functionality of the multimeter language selected. You can take advantage of the full functionality of the 34401A only through the SCPI programming language. For more information on selecting the alternate languages from the front panel menu, see To Select the Programming Language, on the previous page. From the remote interface, use the following commands to select the alternate languages: L1 L2 L3 select SCPI language select Agilent 3478A language select Fluke 8840A language
Virtually all of the commands available for the other two multimeters are implemented in the 34401A, with the exception of the self-test and calibration commands. You must always calibrate the 34401A using the SCPI language setting. The calibration commands from the other two multimeters will not be executed. Be aware that measurement timing may be different in the alternate language compatibility modes.

-160 to -168

-170 to -178
Settings conflict This error can be generated in one of the following situations:
You sent a CONFigure or MEASure command with autorange enabled and with a fixed resolution. Example: CONF:VOLT:DC DEF,0.1 You turned math on (CALC:STAT ON) and then changed to a math operation that was not valid with the present measurement function. For example, dB measurements are not allowed with 2-wire ohms. The math state is turned off as a result of this condition.
Data out of range A numeric parameter value is outside the valid range for the command. Example: TRIG:COUN -3 Too much data A character string was received but could not be executed because the string length was more than 12 characters. This error can be generated by the CALibration:STRing and DISPlay:TEXT commands. Illegal parameter value A discrete parameter was received which was not a valid choice for the command. You may have used an invalid parameter choice. Example: CALC:FUNC SCALE (SCALE is not a valid choice). Data stale A FETCh? command was received but internal reading memory was empty. The reading retrieved may be invalid. Self-test failed The multimeters complete self-test failed from the remote interface (*TST? command). In addition to this error, more specific self-test errors are also reported. See also Self-Test Errors, starting on page 179.
Too many errors The error queue is full because more than 20 errors have occurred. No additional errors are stored until you remove errors from the queue. The error queue is cleared when power has been off, or after a *CLS (clear status) command has been executed. Query INTERRUPTED A command was received which sends data to the output buffer, but the output buffer contained data from a previous command (the previous data is not overwritten). The output buffer is cleared when power has been off, or after a *RST (reset) command has been executed. Query UNTERMINATED The multimeter was addressed to talk (i.e., to send data over the interface) but a command has not been received which sends data to the output buffer. For example, you may have executed a CONFigure command (which does not generate data) and then attempted an ENTER statement to read data from the remote interface. Query DEADLOCKED A command was received which generates too much data to fit in the output buffer and the input buffer is also full. Command execution continues but all data is lost. Query UNTERMINATED after indefinite response The *IDN? command must be the last query command within a command string. Example: *IDN?;:SYST:VERS?

Chapter 7 Measurement Tutorial True RMS AC Measurements

True RMS AC Measurements

True RMS responding multimeters, like the Agilent 34401A, measure the heating potential of an applied voltage. Unlike an average responding measurement, a true RMS measurement is used to determine the power dissipated in a resistor. The power is proportional to the square of the measured true RMS voltage, independent of waveshape. An average responding ac multimeter is calibrated to read the same as a true RMS meter for sinewave inputs only. For other waveform shapes, an average responding meter will exhibit substantial errors as shown below.
The multimeters ac voltage and ac current functions measure the ac-coupled true RMS value. This is in contrast to the ac+dc true RMS value shown above. Only the heating value of the ac components of the input waveform are measured (dc is rejected). For sinewaves, triangle waves, and square waves, the ac and ac+dc values are equal since these waveforms do not contain a dc offset. Non-symmetrical waveforms, such as pulse trains, contain dc voltages which are rejected by ac-coupled true RMS measurements.
Chapter 7 Measurement Tutorial Crest Factor Errors (non-sinusoidal inputs)
An ac-coupled true RMS measurement is desirable in situations where you are measuring small ac signals in the presence of large dc offsets. For example, this situation is common when measuring ac ripple present on dc power supplies. There are situations, however, where you might want to know the ac+dc true RMS value. You can determine this value by combining results from dc and ac measurements as shown below. You should perform the dc measurement using at least 10 power line cycles of integration (6 digit mode) for best ac rejection.

ac + dc =

Crest Factor Errors (non-sinusoidal inputs)
A common misconception is that since an ac multimeter is true RMS, its sinewave accuracy specifications apply to all waveforms. Actually, the shape of the input signal can dramatically affect measurement accuracy. A common way to describe signal waveshapes is crest factor. Crest factor is the ratio of the peak value to RMS value of a waveform. For a pulse train, for example, the crest factor is approximately equal to the square root of the inverse of the duty cycle as shown in the table on the previous page. In general, the greater the crest factor, the greater the energy contained in higher frequency harmonics. All multimeters exhibit measurement errors that are crest factor dependent. Crest factor errors for the Agilent 34401A are shown in the specifications in chapter 8. Note that the crest factor errors do not apply for input signals below 100 Hz when using the slow ac filter.

Crest Factor (continued)

You can estimate the measurement error due to signal crest factor as shown below: Total Error = Error (sine) + Error (crest factor) + Error (bandwidth) Error (sine): error for sinewave as shown in chapter 8. Error (crest factor): crest factor additional error as shown in chapter 8. Error (bandwidth): estimated bandwidth error as shown below.

90-Day and 1-Year Accuracy
These long-term accuracy specifications are valid for a 23C 5C temperature range. These specifications include the initial calibration errors plus the multimeters long-term drift errors.

Temperature Coefficients

Accuracy is usually specified for a 23C 5C temperature range. This is a common temperature range for many operating environments. You must add additional temperature coefficient errors to the accuracy specification if you are operating the multimeter outside a 23C 5C temperature range (the specification is per C).
Chapter 8 Specifications Configuring for Highest Accuracy Measurements
Configuring for Highest Accuracy Measurements
The measurement configurations shown below assume that the multimeter is in its power-on or reset state. It is also assumed that manual ranging is enabled to ensure proper full scale range selection.
DC Voltage, DC Current, and Resistance Measurements:
Set the resolution to 6 digits (you can use the 6 digits slow mode for further noise reduction). Set the input resistance to greater than 10 G (for the 100 mV, 1 V, and 10 V ranges) for the best dc voltage accuracy. Use 4-wire ohms for the best resistance accuracy. Use Math Null to null the test lead resistance for 2-wire ohms, and to remove interconnection offset for dc voltage measurements.
AC Voltage and AC Current Measurements:
Set the resolution to 6 digits. Select the slow ac filter (3 Hz to 300 kHz).
Frequency and Period Measurements:
Set the resolution to 6 digits.
If you have questions relating to the operation of the multimeter, call 1-800-452-4844 in the United States, or contact your nearest Agilent Sales Office.
12 digit, 21, 54 2-wire ohms See two-wire ohms 34398A Cable Kit, 149 34399A Adapter Kit, 149 3478A compatibility, 166 34812A BenchLink Software, 1 4-wire ohms See four-wire ohms 9.90000000E+37, 61, 131
average (min-max) measurements beeper control, 88 description, 39, 64 front-panel, 39 functions allowed, 63, 124
bandwidth detector, 51, 214 bandwidth error, 208 baud rate, 93, 148, 151, 163 beeper continuity threshold, 19 diode threshold, 19 enable/disable, 88 BenchLink software (34812A), 1 BNC connectors Ext Trig, 5, 83 VM Comp, 5, 83 boolean parameters, 159 bumpers, removing, 23 burden voltage, 205, 212 bus triggering, 75, 127

a/d convertor, 55, 57 abort measurement, 76 ac bandwidth detector, 51, 214 ac current connections, 18 math functions allowed, 63, 124 ranges, 18 signal filter, 51, 214 ac settling times, 51 ac signal filter, 51, 214 ac voltage connections, 17 loading errors, 209 math functions allowed, 63, 124 ranges, 17 signal filter, 51, 214 accessories included, 13, 222 accuracy, highest, 229 adapters (RS-232), 149 address, GPIB, 91, 161 addressed commands (IEEE-488), 169 Agilent Express, 6 alternate language compatibility Agilent 3478A, 166 Fluke 8840A/8842A, 167 annunciators, 4 aperture time, 58 automatic trigger delays, 81 autoranging front-panel key, 20 threshold values, 20, 61 auto trigger, 42, 73 autozero definition, 59, 213 vs. integration time, 59 vs. resolution, 59
cables (RS-232), 150 CALCulate:FUNCtion, 63, 124 CALCulate:STATe, 63, 124 CALibration:COUNt?, 98, 146 CALibration:SECure, 97, 146 CALibration:STRing, 99, 147 calibration changing security code, 98 commands, 146 count, 98 errors, 180 message, 99 secure procedure, 97 security code, factory setting, 95 unsecure procedure, 96 carrying handle adjusting, 16 removing, 23 chassis ground, 5 CLEAR, 76 comma separator, 37, 89
command compliance (SCPI), 168 summary, 105-111 syntax conventions, 50, 105, 155 common commands, 169 common mode rejection (CMR), 201 complete self-test, 13, 86 CONFigure, 113, 119 preset state, 110 Conformity, Declaration, 237 connections 2-wire ohms, 17 4-wire ohms, 17 ac current, 18 ac volts, 17 continuity, 19 dc current, 18 dc volts, 17 dcv:dcv ratio, 44 diode, 19 frequency, 18 period, 18 connectors Ext Trig, 5, 83 GPIB interface, 5 RS-232 interface, 5 VM Comp, 5, 83 continuity connections, 19 current source, 19 math functions allowed, 63, 124 threshold resistance, 52 crest factor error, 207, 224 current ac current connections, 18 math functions allowed, 63, 124 ranges, 18 signal filter, 51, 214 dc current connections, 18 math functions allowed, 63, 124 measurement errors, 205 ranges, 18 current input fuses, replacing, 100 current source continuity, 19 diode, 19

Index Index

DATA:FEED, 65, 126, 130 DATA:FEED?, 65, 126, 130 DATA:POINts?, 84, 133 data logging to printer, 91, 160 data types (SCPI), 158 data formats, output, 159 dB measurements description, 40, 67 front-panel, 40 functions allowed, 63, 124 relative value, 40, 67 dBm measurements description, 41, 68 front-panel, 41 functions allowed, 63, 124 resistance values, 41, 68 dc current connections, 18 math functions allowed, 63, 124 measurement errors, 205 ranges, 18 dc input resistance, 53 dc voltage connections, 17 input resistance, 53 loading errors, 199 math functions allowed, 63, 124 ranges, 17 dcv:dcv ratio measurements connections, 44 front panel, 44 math functions allowed, 63, 124 selecting, 45 Declaration of Conformity, 237 delay settling, 204 trigger, 79 DETector:BANDwidth, 51, 123 detector bandwidth, 51, 214 device clear, 152, 157, 160 dielectric absorption, 204 digits, number of, 54, 226 dimensions, product, 223 discrete parameters, 158