Atec Agilent-34972A User Manual

Agilent 34970A
Data Acquisition/
Switch Unit Family

Product Overview
34970A
34972A

Agilent performance

at a fraction of the cost

of other standalone

data acquisition systems

• 3-slot mainframe with built-in 6½ digit DMM and
8 optional switch and control plug-in modules

• Measures and converts 11 different input signals:
temperature with thermocouples, RTDs and thermistors;
dc/ac volts; 2- and 4-wire resistance; frequency and
period; dc/ac current

• IO options for easy connectivity to your PC:
34970A: GPIB, RS-232
34972A: LAN, USB

• Graphical Web interface for point and click monitor and
control (34972A)

• USB flash drive support to copy/log data in standalone
applications (34972A)

• Includes BenchLink Data Logger Software to configure
and control tests, display results and collect data for
further analysis

Table of Contents

3 Features
6 34970A/34972A Power and Flexibility
7 34970A/34972A for your data acquisition applications
10 Using the 34970A/34972A for ATE applications
11 ATE feature checklist
12 Using the 34970A/34972A for switching applications
13 Customize your 34970A/34972A with plug-in modules
13 Modules at a glance selection guide
14 Agilent quality
15 Spec interpretation guide
16 Accuracy specifications
18 System measurement rates
19 System specifications
19 Agilent BenchLink Data Logger Software
20 Modules specifications
21 Multiplexer selection guide (34901A, 34902A, and 34908A)
23 Actuator module (34903A)
23 Matrix module (34904A)
24 RF Multiplexer modules (34905A, 34906A)
25 Multifunction module (34907A)
26 Rack mounting and dimensions
27 Ordering information

2

Features

Price and performance beyond compare

Go ahead and compare the Agilent Technologies 34970A
and 34972A Data Acquisition/Switch Units with other data
acquisition systems currently available. You’ll find it hard to
come up with a system that offers the powerful measure­ment performance, flexibility, connectivity options and ease
of use of the 34970A/34972A—even in systems costing
three to five times as much.

What can you expect from a data
acquisition system that’s this affordable?
Measurements you can trust

We took the measurement engine from our best-selling
benchtop DMM and embedded it inside a 3-slot mainframe.
You get the benefit of proven Agilent measurement perfor­mance, universal inputs with built-in signal conditioning,
and modular flexibility, all in a low-cost, compact data
acquisition package. The 34970A/34972A features 6½
digits (22 bits) of resolution, 0.004% basic dcV accuracy,
and ultra-low reading noise. Combine that with scan rates
of up to 250 channels/sec, and you’ve got the speed and
accuracy you need to get the job done right the first time.

Built-in signal conditioning to get your job done

Whether you need to measure temperature, ac/dc volts,
resistance, frequency, or current, the 34970A/34972A can

handle it. The internal autoranging DMM directly measures
11 different functions, eliminating the need for expensive
external signal conditioning. And our unique design allows
complete per channel configurability for maximum flexibility
and quick, easy set up. It’s like having an independent,
high-performance DMM behind each channel.

Standard connectivity to the PC

Whether you use GPIB, RS-232, LAN or USB interfaces, the
34970A/34972A family offers easy connection to the PC.
The 34970A offers traditional GPIB and RS-232 interfaces.
The 34972A has built-in Gigabit LAN and USB 2.0 so you
can connect to a modern PC without having to purchase
any GPIB cards, cables or converter boxes. With the stan­dard LAN connections you also get the added benefit of a
graphical Web interface for easy configuration of measure­ments and monitoring of results using a standard Web
browser.

Convenient data storage with USB fl ash drive

The 34972A also features a built-in USB memory port so
that you can use a USB flash drive to upload BenchLink
Data Logger configurations into the 34972A and collect
data without being connected to a PC. Data can be logged
directly to the USB flash drive, extending your instrument’s
memory, or copied from internal memory for transfer to a
computer in another location.

3

Easy to use graphical Web interface (34972A only)

The built-in graphical Web interface provides easy access
and control of the instrument using a Java-enabled Web
browser such as Internet Explorer. Using this interface you
can configure measurements, define and execute scan
lists, or monitor measurement results from anywhere on
the network. Simply enter the instrument host name or
IP address into the browser URL and gain access to the
instrument’s capabilities with simple point and click control
right in your browser.

• Specify per channel measurement configuration

• Define and execute switch scans

• Open, close, or monitor switch positions

• Monitor measurement readings

• View and save data

• Send SCPI commands and view IO command log

• View error queue

• View instrument information like module configuration,
relay counts, firmware revisions, and more

Additionally, since the Web interface is built into the
instrument, you can access it on any operating system
that supports a Web browser without having to install
any special software.

Password protection and LAN lock out are also provided
to limit access. The graphical Web interface makes it easy
to configure measurements, set up and execute scans or
troubleshoot your designs from anywhere on the network.

Free BenchLink Data Logger software
saves you time and money

Now you don’t have to spend your valuable time writing
or configuring software. Agilent BenchLink Data Logger
3 software gives you a familiar Microsoft
interface for test configuration and real-time data display
and analysis. Even better, the data logging application is
included with every standard Agilent 34970A/34972A.

®

Windows®

Also available

The BenchLink Data
Logger Pro Software
adds limit checking and
decision making for
more complex applica­tions. Simply identify
the measurements you
want to acquire, define
limits and actions to
be performed, and then
initiate the process. Your
data is then collected,
evaluated and acted on
real-time.

Start

Scan List A

(base)

Events

Scan List C

34832A BenchLink Data Logger Pro adds limit checking and decision making

• Control Instruments

Event

Events

Events

Event

• Send Notification(s)

• Stop Scan

Scan List B

• Control Instruments

• Send Notification(s)

• Stop Scan

Event

• Control Instruments

• Send Notification(s)

• Stop Scan

4

Unequaled ease of use

34970A and 34972A are compatible

From the simplified configuration to the graphical Web
interface in the 34972A, we put in extra time and energy
so you don’t have to. Simple things like on-module screw­terminal connectors, built-in thermocouple reference junc­tions, well-organized user documentation full of examples
and hints, and a standard Getting Started kit that will have
you making measurements in just a few minutes all add up
to increased productivity, whether you use the instrument
every day or only now and then.

Custom confi gurations that grow with you

Three module slots and eight switch/control modules allow
you to customize the 34970A/34972A to meet your unique
requirements. Buy only what you need—and add more
modules later as your application grows.

The 34972A LXI Data Acquisition/Switch Unit is an LXI
version of the 34970A. It replaces the GPIB and RS-232
interfaces with modern connectivity for a direct connection
to your PC or Laptop.

The 8 plug-in modules can be used with either unit—so all
the measurements and wiring are compatible. The 34972A
can be easily integrated into an existing test program with a
simple change to the instrument address. Since the 34972A
code is a superset of the 34970A code, once the instrument
address is changed, the test program will run as normal.

Example:

Change:
Set inst1.IO = ioMgr.Open(“GPIB0::9::INSTR”)

To :
Set inst1.IO = ioMgr.Open(“TCPIP0::156.140.77.230::inst0::
INSTR”)

34970A 34972A

Support 8 plug-in modules ● ●
LabView drivers ● ●
IVI-C, IVI-COM drivers ● ●
BenchLink Data Logger ● ●
Optional BenchLink Data Logger Pro ● ●
Graphical Web interface ●
Gigabit LAN ●
USB 2.0 ●
USB memory port ●
GPIB ●
RS-232 ●

5

More power and fl exibility than you
ever imagined you could afford

6½ digit (22-bit) internal
DMM measures 11 functions without
external signal conditioning

Monitor display
mode lets you
keep an eye on
tests in progress

Scaling function for
converting raw inputs
into user-defined units

HI/LO alarm limits on each input
channel, plus 4 TTL alarm outputs

Intuitive front panel with
task-oriented, self-guiding menus

34972A

50 k readings of non-volatile

memory holds data when

power is removed

Battery-backed real-time clock for pacing

scans and timestamping readings

• Offers up to 96 matrix
crosspoints or
120 single-ended channels

• 8 switch and control plug-in
modules to choose from

• Agilent BenchLink Data
Logger 3 Agilent VEE,

IVI-C, IVI-COM and
National Instruments
LabVIEW drivers included

6

USB

USB memory port to log/

transfer data to a USB flash drive

Built-in LAN and USB for instant connection to a PC

34970A

GPIB

34970A built-in GPIB and RS-232 interfaces

The Agilent 34970A/34972A offers unequaled versatility
for your data acquisition applications

In the past, you had to make a choice. On the one hand,
you could choose the simple operation and low cost of a
data logger. On the other hand, you had the flexibility and
higher performance of a modular data acquisition system.
The Agilent 34970A/34972A Data Acquisition/Switch Unit
gives you the best of both worlds: a simple user interface
with low per-channel cost, modular flexibility, standard
connectivity and impressive measurement performance.

Whether you’re an R&D engineer working on character­izing your latest design, or a manufacturing engineer
building a test system or troubleshooting a process, the
34970A/34972A Data Acquisition/Switch Unit offers the
best combination of price and measurement performance.

It’s a data logger

Configured with a 20-channel relay multiplexer, the
34970A/34972A becomes a powerful, low-cost data logger
for simple characterization applications. What’s more,
the 34972A with its LAN and USB interfaces is ideal for
easy set up and control for data logging applications
in remote locations. For more information on using the
34970A/34972A for data logging applications, see page 8.

It’s a data acquisition front end

The 34970A/34972A is an automated test system with
excellent measurement performance—it’s got the accuracy,
resolution, and speed you need. See page 10 for application
information.

It’s a switch system

Order the mainframe without the internal DMM and you’ve
got an even lower cost, high-quality signal routing solution.
See page 12 for details.

7

An easy-to-use data logger for monitoring
and characterization applications

Data loggers are used to monitor multiple signals (tempera­ture, voltage, etc.) over extended periods of time to identify
irregularities. Example applications include environmental
chamber monitoring, component inspection, benchtop test­ing, process troubleshooting, and temperature profiling.

applications. Use GPIB (IEEE 488) or RS-232 interfaces
in the 34970A for legacy systems or use the 34972A with
standard LAN and USB interfaces for simple connection
to the PC and support of remote applications. The 34972A
can be set up at remote locations and accessed through
the Web interface on a network connection or through
the USB port by copying instrument configurations and
measurement data results to a USB flash drive.

The Agilent 34970A/34972A is easy to use for a multitude
of data logging and monitoring applications, either stand­alone or with a computer. Its flexible, modular design
makes it scalable from 20 to 120 channels, and lets you
add actuator, digital I/O, and analog output channels for
simple control. Its small size, ruggedized features and USB
memory port on the 34972A make it perfect for portable

Simplify your data gathering with
Agilent BenchLink Data Logger 3 software

Do you want PC-based data logging capability, but don’t
want to spend hours programming? The BenchLink Data
Logger 3 software is the answer. This Windows-based
application is designed to make it a snap to use your PC
for gathering and analyzing measurements. Use it to set
up your test, acquire and archive measurement data, and
perform real-time display and analysis of the incoming
measurements.

A familiar spreadsheet environment makes it easy to
configure and control your tests. And a rich set of color­ful graphics provides many options for analyzing and
displaying your data—all with point-and-click ease. Set up
multiple graphics using strip charts, histograms, bar and
scatter charts, individual channel results, and more. And
of course you can use BenchLink Data Logger 3 to easily
move data to other applications for further analysis, or for
inclusion in your presentations and reports.

Better measurements with fewer hassles

Tired of putting up with the mediocre measurement
performance you get with most data loggers or plug-in data
acquisition boards? The 34970A/34972A offers 6½ digits of
resolution and 0.004% basic 1-year dcV accuracy.

The BenchLink Data Logger software can run connected
to the computer, standalone in the instrument or even over
the network when using the LAN interface on the 34972A.

8

And the 34970A/34972A measures and converts
11 different input signals:

• temperature with thermocouples, RTDs,

and thermistors

• dc and ac volts

• 2- and 4-wire resistance

• frequency and period

• dc and ac current
What’s more, each channel is independently configurable.

This means you can configure channel 1—for dcV, channel
2 for a K-type thermocouple, and channels 3 and 13 for a
4-wire RTD measurement—all on the same module, all in a
single scan. For custom linear conversions, use the Mx+B
scaling function on any channel. You can even display a
custom 3-character engineering label like RPM or PSI to
identify your measurement units.

Versatile alarms

Alarms are available on a per-channel basis as well.
Enter a high limit, a low limit, or both. The 34970A/34972A
compares each reading to its limits and flags any out-of­range measurements. You can assign one of four TTL
alarm outputs to any input channel to trigger external
alarm lights, sirens, or send a TTL pulse to your control
system, all without a PC connected.

Monitor any input

A special display mode monitors a selected input channel,
continuously updating the display with new readings—even
during a scan. Or, when using the 34972A with built-in LAN,
the channels can be monitored over the network using the
graphical Web interface. It’s great for keeping an eye on a
key input, or for troubleshooting your system before a test.

Non-volatile memory and USB fl ash drive adds
convenience, portability

All readings are automatically time-stamped and stored in
a nonvolatile 50,000 reading memory—enough memory
to hold more than a week’s worth of data (20 channels
scanned every five minutes). The nonvolatile memory holds
your data even after power is removed, so you can use the
34970A/34972A to collect data at a remote location for
later uploading to a PC. Or if you need even more memory,
the 34972A’s USB port can be used to log data directly
to a USB flash drive or to copy the data from the reading
memory without being connected to a computer.

Data logging feature checklist

• From 1 to 120 channels of analog input

Scanning made simple

The 34970A/34972A automatically builds a scan list that
includes all configured inputs (even digital inputs from the
Agilent 34907A multifunction module) in ascending order
by channel number. You can pace scans by setting the
34970A/34972A’s internal timer for automatic scanning
at a specific interval, by manually pressing a front-panel
button, or by sending a software command or external
TTL trigger pulse.

• Measurements include dc volts, ac volts, thermo­couple, thermistor and RTD temperature measure­ments, 2- and 4-wire Ohms, dc current, ac current,
frequency, and period

• 6½ digits (22 bits) of resolution with 0.004% basic
1-year dcV accuracy

• 50 k reading nonvolatile memory including time­stamp

• Scaling and alarms available on each channel

• Full-featured front panel for stand-alone configura­tion, troubleshooting, and data viewing

• BenchLink Data Logger 3 software for configura­tion and data analysis

• Nonvolatile storage for five complete instrument
states

• Built-in LAN or USB interfaces to support remote
data logging applications (34972A only)

9

A powerful, fl exible data acquisition system
for automated test

The 34970A/34972A gives you the resolution, accuracy,
repeatability, and speed you’ve come to expect from an
Agilent data acquisition system. It provides the measure­ment muscle you need, along with signal routing and
control capability, in a flexible, modular format that can
grow and change to match your varied applications.

Powerful measurements

The internal 6½ digit DMM brings the power and
performance of a world-class stand-alone DMM to the
34970A/34972A, but at a fraction of the cost and in a
fraction of the space. It’s as accurate as the best bench
DMM available: 0.004% basic 1-year dcV accuracy, 0.06%
basic 1-year acV accuracy, and 0.01% basic 1-year resistance
accuracy. Our patented Multi-slope III A-D technology
offers incredible linearity (2 ppm of reading +1 ppm of
range) along with 22 bits of real resolution. And since it is
an integrating A/D, it provides excellent noise rejection as
well—a nice change from noisy PC plug-ins and sampling
A/Ds. No more averaging lots of samples just to see the
real data you wanted. And if you need high scan rates, the
34970A/34972A is capable of delivering fully converted
measurements at speeds up to 250 ch/s.

The input section of the DMM is optically isolated and
shielded from the 34970A/34972A’s earth-referenced cir­cuitry and computer interface, offering up to 300 V of input
isolation. This is important for reducing ground loop and
common mode voltage errors associated with long wiring
runs and floating measurement sources.

Flexible functionality

The DMM is installed inside the chassis rather than in
one of the slots, leaving all three mainframe slots free for
switch and control modules. You can choose from eight
different modules (see page 13) to get the precise function­ality you need now—while giving you flexibility for future
expansion.

The internal DMM gives you the flexibility to measure
11 types of inputs easily and inexpensively. The built-in
signal conditioning and conversion routines turn raw inputs
directly into real information. Each measurement channel is
independently configurable, so you can set different mea­surement functions, scale factors and alarm limits, even on
adjacent channels. Advanced measurement features such
as offset compensation, variable integration time, and delay
are also selectable on a per-channel basis.

Get better measurements with built-in
signal conditioning

The Agilent 34970A/34972A architecture offers
advantages over other data acquisition solutions
which rely on external or plug-in signal conditioning
modules for handling functions other than dcV:

• Minimizes external wiring and the resultant poten­tial for noise and errors to enter your system

• Reduces hidden costs and overall system cost by
avoiding unnecessary cables, breakout boxes and
signal conditioning elements

• Simplifies your configuration—for faster, easier
setup—with fewer connections and components

10

• Takes the guesswork out of error analysis.
Measurement accuracies are specified to include
all system-related errors

• Improves reliability, with fewer interconnects and
fewer parts that can fail

Software drivers

Your months of test system software development
time need not go to waste. Software drivers that
support (C, C#, Visual Basic, Visual Studio)®, Agilent VEE
and National Instruments LabView are available for the
34970A/34972A to make integration into your test system
easy. Standard RS-232 and GPIB interfaces on the 34970A
or LAN and USB on the 34972A and SCPI programming
language make integration even easier.

ATE feature checklist

• 3-slot cardcage with 6½ digit (22 bit) internal DMM

• 0.004% basic 1-year dcV accuracy; 0.06% acV
accuracy

• Up to 120 single-ended measurements or 96 matrix
crosspoints in a 3½” high, half-rack instrument

• Eight switch and control modules include low­frequency and RF multiplexers, matrix and actuation
switches, digital input and output, analog output,
and event recording

• Scan rates up to 250 ch/s

• GPIB and 115 kbaud RS-232 interfaces standard
(34970A)

• Graphical Web interface to speed up test
development and monitor tests remotely (34972A)

• Software drivers available to support Agilent VEE
and National Instruments LabView

• Relay maintenance feature for system maintenance

Compact 60-channel data acquisition system

11

Low-cost, high-quality switching for
automated test

If you don’t need the built-in measurement capability of
the 34970A

DMM. What you end up with is the lowest cost switch unit
on the market. It’s an ideal solution for routing test signals
to and from your DUT and assorted instruments, including
external DMMs, scopes, counters, and power supplies.
Plus, you can add the DMM later if your needs change.

/34972A

, save money by ordering it without the

The functionality you need

We put a lot of thought into defining and designing the
modules for the 34970A

spectrum of switching and signal routing requirements
with fewer modules. The result? Simplified ordering and
easier configuration. And while we were at it, we improved

performance

and density. The 34970A/34972A modules can

/34972A

switch from microvolts to 300 volts, dc to 2 GHz, and with
densities as high as 120 single-ended channels or 96 matrix
crosspoints per frame. Plus, simple control capabilities like
analog outputs, open collector digital outputs, and isolated
Form-C relays for controlling higher-powered devices are
available.

in order to cover a broad

Easy scanning

The 34970A/34972A can easily scan with external
instruments. It builds a scan list that includes all enabled
low frequency multiplexer inputs. Scans are controlled with
the external “channel advance” input, or with the front
panel “Step” key.

Connect to the company network

With the 34972A’s LAN interface, the instrument is easily
connected to the company network to collect measurement
data to a central database, remotely access the instrument’s
set up, or monitor measurement data from anywhere on
the network.

Low-cost switching system for automated testing

12

Customize your Agilent 34970A/34972A with
plug-in modules

A complete selection of plug-in modules gives you high
quality measurement, switching, and control capabilities to
choose from. Modules include both low-frequency and RF
multiplexers, a matrix switch, a general-purpose switch, and
a multifunction module that includes digital input/output,
analog output, and totalizer capabilities. You can mix and
match modules to get just the functionality you need right
now—then change or add more channels later as your
application grows.

More channels in less space

Surface mount construction and a highly integrated design
minimize the space required for relay drive and interface
circuitry. High density on-module connectors save both
board and connector space normally required by a terminal
block. We use the latest technology to squeeze the most
out of the remaining board space, giving you up to
40 single-ended channels in roughly the same space
used by many data acquisition system terminal blocks.

Convenient connections

Modules for the 34970A/34972A are designed to make your
testing easier, faster, and more reliable. Here’s how:

On-module screw-terminal connectors make wiring more
convenient. Built-in strain relief cable routing and cable tie
points keep your wiring secure and safe from accidental

Higher throughput

tugs and pulls. An internal analog bus routes signals from
any of the low frequency multiplexers directly to the inter-

Our unique architecture incorporates a high-performance

nal DMM, without the need for external connections.

microprocessor on each module, off loading the mainframe
processor and minimizing backplane communications for
faster throughput.

Use the chart below to help you pinpoint the modules that
meet your needs.

34970A and 34972A Agilent modules-at-a-glance selection guide

Model description Type Speed

(ch/sec)

34901A
20 ch Multiplexer
+ 2 current channels

34902A
16 ch Multiplexer

34903A
20 ch Actuator/GP Switch

34904A 4 x 8 Matrix 2-wire armature 120 300 V 1 A 10 MHz < 3 µV 23
34905A

Dual 4 ch RF Mux 50Ω
34906A

Dual 4 ch RF Mux 75Ω
34907A

Multifunction Module

34908A
40 ch Single-Ended Mux

[1] Up to 250 ch/sec to internal memory.

See scanning rates for measurement condition and rate on each instrument.

2-wire armature
(4-wire selectable)

2-wire reed
(4-wire selectable)

SPDT/form C 120 300 V 1 A 10 MHz < 3 µV 23

Common low
(unterminated)

Common low
(unterminated)

Two 8-bit digital I/O ports 42 V 400 mA Open drain 25
26-bit event counter 42 V 100 KHz Selectable input threshold
Two 16-bit analog outputs ± 12 V 10 mA dc Max 40 mA total output per

1-wire armature
(common low)

250

Max
volts

60 300 V 1 A 10 MHz < 3 µV Built-in cold junction reference

[1]

300 V 50 mA 10 MHz < 6 µV Built-in cold junction reference 21

60 42 V 0.7 A 2 GHz < 6 µV 1 GHz bandwidth through

60 42 V 0.7 A 2 GHz < 6 µV 1 GHz bandwidth through

60 300 V 1A 10 MHz < 3 µV Built-in cold junction reference

Max

Bandwidth Thermal

amps

Comments Page

offset

2 additional current channels
(22 total)

BNC-to-SMB adapter cable

BNC-to-SMB adapter cable

frame

No four-wire measurements

21

24

24

21

13

Agilent quality

Take the guesswork out of relay maintenance

We know you can’t afford instrument downtime due
to hardware failures and unscheduled maintenance.
That’s why our engineers designed reliability into the
34970A/34972A: A rugged enclosure, state-of-the-art
surface mount construction throughout, reduced parts
counts, and rigorous and thorough testing on all aspects
of the product.

The 34970A/34972A uses our proprietary relay mainte­nance system to help you to predict relay end-of-life and
avoid costly production line downtime. It automatically
counts every individual switch closure and stores it in
nonvolatile memory on each module. You can query the
total number of cycles on any individual channel so you can
schedule maintenance and avoid erratic end-of-life failures.

14

Spec interpretation guide

Example 2: Extreme operating temperature

The following pages list the technical specifications for
the Agilent 34970A/34972A Data Acquisition/Switch Unit
and its modules. The explanations and examples below
are helpful in understanding how to interpret these
specifications:

• Measurement accuracy is specified as percent of
reading plus percent of range, where reading is the
actual measured value and range is the name of the
scale (1 V, 10 V, etc.)—not the full scale value (1.2 V,
12 V, etc.).

• DMM measurement accuracies include all switching
errors. Switching errors are also listed separately in the
module specifications section. Temperature measurement
accuracies include ITS-90 conversion errors. The thermo­couple accuracies include the reference junction error
as well.

• Accuracies are listed as either 24-hour, 90-day, or 1-year
specifications. This refers to the length of time since the
instrument’s last calibration. Use the specification that
matches your calibration cycle. The 24-hour specifica­tions are useful for determining short-term relative
performance.

Example 1: Basic dcV accuracy

When the 34970A/34972A is used outside of its 18 °C –
28 °C temperature range, there are additional temperature
drift errors to consider. Assume the same conditions in
Example 1, but at a 35 °C operating temperature.

The basic accuracy is again:

0.0035% of reading + 0.0005% of range = 365 µV.

Now, multiply the 10 V temperature coefficient from the
following page by the number of degrees outside of
operating range for additional error:
(0.0005% reading + 0.0001% range)
/ °C x (35 °C - 28 °C) =
(0.0005% reading + 0.0001% range)
/ °C x 7 °C =

0.0035% reading + 0.0007% range = 385 µV
Total error is then:
365 µV + 385 µV = 750 µV or 0.008%

Example 3: Thermocouple measurement accuracy

Calculating the total thermocouple reading error is easy
with the 34970A/34972A—just add the listed measurement
accuracy to the accuracy of your transducer. Switching,
conversion, and reference junction errors are already
included in the measurement specification.

Calculate the accuracy of the following measurement:

9 V dc input
10 V dc range
1-year accuracy specifications
Normal operating temperature (18 °C – 28 °C)

From the following page, the 1-year accuracy is:

0.0035% of reading + 0.0005% of range

Which translates into:
(0.0035/100 x 9 V)+
(0.0005/100 x 10 V) = 365 µV

For a total accuracy of:
365 µV / 9 V = 0.0041%

For this example, assume a J-type thermocouple input
reading 150° C.

From the following page, total error is:
Thermocouple probe accuracy + 1.0 °C
The probe vendor specifies accuracy of 1.1 °C
or 0.4%, whichever is greater.

Total error is then:

1.0ºC + 1.1ºC = 2.1ºC total, or 1.4%

Example 4: acV accuracy

The acV function measures the true RMS value of the input
waveform, regardless of waveshape. Listed accuracies
assume a sinewave input. To adjust accuracies for non­sinusoids, use the listed crest factor adder.

For this example, assume a ± 1 V square wave input with
50% duty cycle and a 1 kHz frequency.

Accuracy for 1 V, 1 kHz sinusoid is:

0.06% reading + 0.04% range
A 50% duty cycle squarewave has a crest factor of
Peak value / RMS value = 1 V / 1 V = 1

From crest factor table, add:

0.05% of reading

The total accuracy is:

0.11% of reading + 0.04% of range = 1.5 mV or 0.15%

15

34970A/34972A accuracy specifi cations ± (% of reading + % of range)

[1]

Includes measurement error, switching error, and transducer conversion error

[3]

Range

Frequency, etc. 24 hour

DC voltage

100.0000 mV 0.0030 + 0.0035 0.0040 + 0.0040 0.0050 + 0.0040 0.0005 + 0.0005

1.000000 V 0.0020 + 0.0006 0.0030 + 0.0007 0.0040 + 0.0007 0.0005 + 0.0001

10.00000 V 0.0015 + 0.0004 0.0020 + 0.0005 0.0035 + 0.0005 0.0005 + 0.0001

100.0000 V 0.0020 + 0.0006 0.0035 + 0.0006 0.0045 + 0.0006 0.0005 + 0.0001

300.000 V 0.0020 + 0.0020 0.0035 + 0.0030 0.0045 + 0.0030 0.0005 + 0.0003

True RMS AC voltage

[4]

All ranges from

100.0000 mV
to 100.0000 V

3 Hz–5 Hz 1.00 + 0.03 1.00 + 0.04 1.00 + 0.04 0.100 + 0.004
5 Hz–10 Hz 0.35 + 0.03 0.35 + 0.04 0.35 + 0.04 0.035 + 0.004
10 Hz–20 kHz 0.04 + 0.03 0.05 + 0.04 0.06 + 0.04 0.005 + 0.004
20 kHz–50 kHz 0.10 + 0.05 0.11 + 0.05 0.12 + 0.05 0.011 + 0.005
50 kHz–100 kHz 0.55 + 0.08 0.60 + 0.08 0.60 + 0.08 0.060 + 0.008
100 kHz–300 kHz

[5]

300.0000 V 3 Hz–5 Hz 1.00 + 0.05 1.00 + 0.08 1.00 + 0.08 0.100 + 0.008
5 Hz–10 Hz 0.35 + 0.05 0.35 + 0.08 0.35 + 0.08 0.035 + 0.008
10 Hz–20 kHz 0.04 + 0.05 0.05 + 0.08 0.06 + 0.08 0.005 + 0.008
20 kHz–50 kHz 0.10 + 0.10 0.11 + 0.12 0.12 + 0.12 0.011 + 0.012

Resistance

50 kHz–100 kHz 0.55 + 0.20 0.60 + 0.20 0.60 + 0.20 0.060 + 0.020

[6]

100 kHz–300 kHz

[5]

100.0000 Ω 1 mA current source 0.0030 + 0.0035 0.008 + 0.004 0.010 + 0.004 0.0006 + 0.0005

1.000000 kΩ 1 mA 0.0020 + 0.0006 0.008 + 0.001 0.010 + 0.001 0.0006 + 0.0001

10.00000 kΩ 100 µA 0.0020 + 0.0005 0.008 + 0.001 0.010 + 0.001 0.0006 + 0.0001

100.0000 kΩ 10 µA 0.0020 + 0.0005 0.008 + 0.001 0.010 + 0.001 0.0006 + 0.0001

1.000000 MΩ 5.0 µA 0.002 + 0.001 0.008 + 0.001 0.010 + 0.001 0.0010 + 0.0002

10.00000 MΩ 500 nA 0.015 + 0.001 0.020 + 0.001 0.040 + 0.001 0.0030 + 0.0004

100.0000 MΩ 500 nA || 10 MΩ 0.300 + 0.010 0.800 + 0.010 0.800 + 0.010 0.1500 + 0.0002

Frequency and period

[7]

100 mV 3 Hz–5 Hz 0.10 0.10 0.10 0.005
to 300 V 5 Hz–10 Hz 0.05 0.05 0.05 0.005

10 Hz–40 Hz 0.03 0.03 0.03 0.001
40 Hz–300 kHz 0.006 0.01 0.01 0.001

DC current (34901A only)

10.00000 mA <0.1 V burden 0.005 + 0.010 0.030 + 0.020 0.050 + 0.020 0.002+ 0.0020

100.0000 mA <0.6 V 0.010 + 0.004 0.030 + 0.005 0.050 + 0.005 0.002 + 0.0005

1.000000 A <2 V 0.050 + 0.006 0.080 + 0.010 0.100 + 0.010 0.005 + 0.0010

True RMS AC current (34901A only)

10.00000 mA 3 Hz–5 Hz 1.00 + 0.04 1.00 + 0.04 1.00 + 0.04 0.100 + 0.006

[4]

1.000000 A 5 Hz–10 Hz 0.30 + 0.04 0.30 + 0.04 0.30 + 0.04 0.035 + 0.006

and

10 Hz–5 kHz 0.10 + 0.04 0.10 + 0.04 0.10 + 0.04 0.015 + 0.006
3 Hz–5 Hz 1.00 + 0.5 1.00 + 0.5 1.00 + 0.5 0.100 + 0.06

100.0000 mA

[8]

5 Hz–10 Hz 0.30 + 0.5 0.30 + 0.5 0.30 + 0.5 0.035 + 0.06
10 Hz–5 kHz 0.10 + 0.5 0.10 + 0.5 0.10 + 0.5 0.015 + 0.06

Temperature Type 1-year accuracy

Thermocouple

[10]

B 1100 °C to 1820 °C 1.2 °C 400 °C to 1100 °C 1.8 °C

[9]

E -150 °C to 1000 °C 1.0 °C -200 °C to -150 °C 1.5 °C
J -150 °C to 1200 °C 1.0 °C -210 °C to -150 °C 1.2 °C
K -100 °C to 1200 °C 1.0 °C -200 °C to -100 °C 1.5 °C 0.03 °C
N -100 °C to 1300 °C 1.0 °C -200 °C to -100 °C 1.5 °C
R 300 °C to 1760 °C 1.2 °C -50 °C to 300 °C 1.8 °C
S 400 °C to 1760 °C 1.2 °C -50 °C to 400 °C 1.8 °C
T -100 °C to 400 °C 1.0 °C -200 °C to -100 °C 1.5 °C

RTD R
Thermistor 2.2 k, 5 k, 10 k -80 °C to 150 °C 0.08 °C 0.002 °C

from 49 Ω to 2.1 kΩ -200 °C to 600 °C 0.06 °C 0.003 °C

0

[2]

23 °C ± 1 °C

90 Day
23 °C ± 5 °C

1 Year
23 °C ± 5 °C

Temperature
coeffi cient
0 °C–18 °C, 28 °C–55 °C

4.00 + 0.50 4.00 + 0.50 4.00 + 0.50 0.20 + 0.02

4.00 + 1.25 4.00 + 1.25 4.00 + 1.25 0.20 + 0.05

Extended range 1-year accuracy

[9]

Temp coeffi cient/ºC

[1] Specifi cations are for 1 hr warm-up and 6½ digits, Slow ac fi lter
[2] Relative to calibration standards
[3] 20% over range on all ranges except 300 Vdc and ac ranges and 1 Adc and

ac current ranges

[4] For sinewave input > 5% of range. For inputs from 1% to 5% of range and <

50 kHz, add 0.1% of range additional error

[5] Typically 30% of reading error at 1 MHz, limited to 1 x 10

8

V Hz

16

[6] Specifi cations are for 4- wire ohms function or 2-wire ohms using scaling to

remove the offset. Without scaling, add 4 Ω additional error in 2-wire Ohms

function
[7] Input > 100 mV. For 10 mV to 100 mV inputs multiply % of reading error x 10
[8] Specifi ed only for inputs >10 mA
[9] For total measurement accuracy, add temperature probe error
[10] Thermocouple specifi cations not guaranteed when 34907A module

is present. For < 1 °C accuracy, a precision external reference is required.

Measurement characteristics

[7]

Operating characteristics

[4]

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
100 mV, 1 V, 10 V ranges Selectable 10 MΩ or > 10,000 MΩ
100 V, 300 V ranges 10 MΩ ± 1%
Input bias current < 30 pA at 25 °C
Input protection 300 V all ranges

True RMS AC voltage

Measurement method AC coupled True RMS — measures the
AC component of the input with up to
300 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 MΩ ± 2% in parallel with 150 pF
Input protection 300 Vrms all ranges

Resistance

Measurement method Selectable 4-wire or 2-wire Ohms
Current source referenced to LO input
Offset compensation Selectable on 100 Ω, 1 kΩ, 10 kΩ ranges
Maximum lead resistance 10% of range per lead for 100 Ω and
1 kΩ ranges. 1 kΩ on all other ranges
Input Protection 300 V on all ranges

Single channel measurement rates

Function Resolution

[5]

[8]

34970A/34972A

readings/sec

dcV, 2-wire resistance 6½ digits (10 plc) 6 (5)

5½ digits (1 plc) 54 (47)
4½ digits (0.02 plc) 500

Thermocouple 0.1 °C (10 plc) 6 (5)

0.1 °C (1 plc) 52 (47)
(0.02 plc) 280

RTD, thermistor 0.01 °C (10 plc) 6 (5)

0.1 °C (1 plc) 49 (47)
1 °C (0.02 plc) 200

acV 6½ Slow (3 Hz) 0.14

6½ Med (20 Hz) 1
6½ Fast (200 Hz) 8

[6]

6½

Frequency, period 6½ digits (1 s gate) 1

5½ digits (100 ms) 9
4½ digits (10 ms) 70

100

Frequency and period

Measurement method Reciprocal counting technique
Voltage ranges Same as AC Voltage function
Gate time 1s, 100 ms, or 10 ms
Measurement timeout Selectable 3 Hz, 20 Hz, 200 Hz LF limit

DC Current

Shunt resistance 5Ω for 10 mA, 100 mA; 0.1 Ω for 1 A
Input protection 1A 250 V fuse on 34901A module

True RMS AC current

Measurement method Direct coupled to the fuse and shunt.
AC coupled True RMS measurement
(measures the ac component only)
Shunt resistance 5 Ω for 10 mA; 0.1 Ω for 100 mA, 1 A
Input protection 1 A 250 V fuse on 34901A module

Thermocouple

Conversion ITS-90 software compensation
Reference junction type Internal, Fixed, or External
Open thermocouple check Selectable per channel. Open > 5 kΩ

Thermistor 44004, 44007, 44006 series

RTD α = 0.00385 (DIN) and α = 0.00391

Measurement noise rejection 60 (50) Hz

[1]

dc CMRR 140 dB
ac CMRR 70 dB
Integration time Normal mode rejection
200 plc/3.33s (4s) 110 dB
100 plc/1.67s (2s) 105 dB
20 plc/333 ms (400 ms) 100 dB
10 plc/167 ms (200 ms) 95 dB

[3]

[3]

[3]

[3]

[2]

2 plc/33.3 ms (40 ms) 90 dB
1 plc/16.7 ms (20 ms) 60 dB
< 1 plc 0 dB

[1] For 1 KΩ unbalance in LO lead
[2] For power line frequency ± 0.1%
[3] For power line frequency ± 1% use 80 dB or ± 3% use 60 dB
[4] Reading speeds for 60 Hz and (50 Hz) operation
[5] For fi xed function and range, readings to memory, scaling and

alarms off, AZERO OFF, USB datalogging OFF
[6] Maximum limit with de fault settling delays defeated
[7] Isolation voltage (ch-ch, ch-earth) 300 Vdc, ac rms
[8] 6½ digits = 22 bits, 5½ digits = 18 bits, 4½ digits = 15 bits

17

Single channel reading rates to I/O or internal memory

(See footnotes for conditions below) 34970A 34972A

into memory

readings/sec

to GPIB or RS232

readings/sec

to LAN, USB or

memory

readings/sec

Single channel ASCII readings 500 440 500
Single channel while changing scale

25 25 25
(eg MEAS dcV 10/MEAS dcV 1)
Single channel while changing function

12 12 12
(eg MEAS dcV/MEAS Ohms)

Scanning measurement rates to I/O or internal memory

(See footnotes for conditions below) 34970A 34972A

into memory

ch/sec

Scanning dcV or ohms channels

34901A/34908A 60 60 60
34902A 250 210 240
34902A into and out of memory (using INIT, FETCh) — 180 240
34902A with timestamp (using MEAS) — 150 240
34902A with scaling and alarms 220 190 220
34902A dcV and ohms on alternate channels 80 80 80

Scanning acV channels

(2)

34901A/34908A 50 50 50
34902A 100 90 100

Scanning temperature – thermistor or TC channels

34901A/34908A 50 50 50
34902A 160 150 150

Scanning digital in/totalizer channels

34907A Digital Input 275 250 275
34907A Totalizer 240 210 240

to GPIB or RS232

ch/sec

to LAN, USB or

memory

ch/sec

Data out of memory

(3)(4)

(FETCh of 50K readings)

(See footnotes for conditions below) 34970A 34972A

Single channel

[1] [2]

over GPIB

readings/sec

over RS232

readings/sec

over USB

readings/sec

over LAN or

memory

readings/sec

Readings 800 600 55 K 120 K
Readings with timestamp 450 320 35 K 60 K
Readings with all format options ON 310 230 25 K 50 K

[1] Speeds are for 4 1/2 digits, delay 0, display off, USB data logging off, autozero off, auto-ranging off unless otherwise noted. Use MEAS command

for best I/O performance. RS232 at 115 Kbaud.
[2] Maximum, with default delays defeated
[3] Assumes relative time format (time since start of scan)
[4] Typical rates assuming lightly loaded PC and limited other traffi c on I/Os. LAN rates assume use of socket connection; VXI11 will be less.
[5] For fi xed function and range, readings to memory, scaling/alarms/autozero off

18

System specifi cations

Software

Scanning inputs

Analog 34901A, 34902A, and 34908A
multiplexer channels
Digital 34907A digital in and totalize
Scan list Scans channels in ascending order

Agilent 34825A BenchLink Data Logger 3

(included with option DMM)

System requirements

Operating system Windows Vista®, XP SP2, 2000 SP4 (does
not support any home editions),

Scan triggering

Source Interval, external, button press, software,
or on monitor channel alarm
Scan count 1 to 50,000 or continuous
Scan interval 0 to 99 hours; 1 ms step size
Channel delay 0 to 60 seconds per channel; 1 ms step size
External trig delay <300 µs. With monitor on <200 ms
External trig jitter <2 ms

Adobe® Acrobat® Reader V5.0 or higher
(to view documentation)
Microsoft Internet Explorer V6.0 or higher
(required when using Windows NT)
Controller Recommend Pentium
greater, Min: Pentium III, 500 MHz
RAM Recommend 256 MB or greater,
Min 128 MB
Disk space Recommend 200 MB, Min 100 MB

Alarms

Analog inputs Hi, Lo, or Hi + Lo evaluated each scan
Digital inputs 34907A digital in maskable pattern match
or state change
34907A totalize: Hi limit only
Monitor channel Alarm evaluated each reading
Alarm outputs 4 TTL compatible
Selectable TTL logic Hi or Lo on fail
Latency 5 ms (typical)

Memory

Battery 34970A, 4-year typical life

[1]

,
34972A User replaceable battery.
Recommend replacement once a year
during CAL.
Readings 50,000 internal readings with timestp
Readable during scan
States 5 instrument states with user label
Alarm queue Up to 20 events with channel number,
reading, and timestamp
USB flash drive Support FAT or FAT 32 format

Display Recommend 1024 x 768 resolution,
256 colors

Computer interfaces
34970A

GPIB Agilent and National Instruments PCI-GPIB
RS-232 (Serial port) PC COM 1-4
34972A
LAN 10/100/1000 BaseT
USB USB 2.0

Agilent BenchLink features

Configuration Spreadsheet-like channel configurations
page.
Upload and Download instrument
configurations.
Computed channels using ± */, dB, dBm,
dBV, x
Graphical displays Real-time and historical data displays
Add, delete, size, and configure real time
Strip chart with markers and alarm indication,
bar and scatter charts, Histogram with
statistics, Bar meter, and Data table

System features

Per-channel math Individual Mx + B scaling and
Min/Max/Average calculated real time
Power fail recovery Resumes scanning automatically
Relay maintenance Counts each relay closure and stores
on module User resettable
Real-time clock Battery-backed, 4-year typical life

[1]

Graphical controls Sliders, switches, buttons, and LED lights
Alarm/limit testing Start/Stop scanning on alarm condition
Control 34903A relay state or 34907A
digital output on alarm
Data Real time streamed (saved) to disk
Automatically export data and
configurations
Copy data or graphics to windows clipboard

General specifications

Power supply 100 V/120 V/220 V/240 V ± 10%
Power line frequency 45 Hz to 66 Hz automatically sensed

Export your selected data to .CVS, .XML,
or .TXT formats
Event logging Automatic entry of alarms and errors

Power consumption 12 W (25 VA peak)
Operating environment Full accuracy for 0 °C to 55 °C
Full accuracy to 80% R.H. at 40 °C
Storage environment -40 °C to 70 °C

[1]

Weight Net: 3.6 kg (8.0 lbs)
Safety Conforms to CSA, UL-1244, IEC 1010 Cat I
RFI and ESD CISPR 11, IEC 801/2/3/4

Instrument driver support for programming languages

IVI-C or IVI-COM driver Compatible with Windows
XP SP2 (32-bit) IO Libraries 14.1 or greater.
Supports Agilent VEE, Visual Basic, C/C#,
Visual Studio, National Instruments
LabWindows CVI and LabVIEW
LabVIEW driver (VI) LabVIEW 7.0 or greater

[1] Storage at temperatures above 40 °C will decrease battery life
[2] Software provided on CD-ROM

Controller Recommend 800 MHz or greater,
minimum 600 MHz.

[3] Interface and driver must be purchased and installed separately
[4] Requires VISA command library for IEEE-488

[2]

®

4, 800 MHz or

[3]

2

, √―x and full, ½, or ¼ bridge strain

®

7, Vista SP1,

19

Modules specifi cations

The Agilent 34970A/34972A accuracy specifications already
include the switching offset and reference junction errors
shown below. These errors are listed separately for deter­mining system error with external measurement devices.

Up to three modules, in any combination, can be inserted
into a single mainframe. The 34970A/34972A’s internal

DMM connections are accessible only through the 34901A,
34902A, and 34908A low-frequency multiplexers.

On-module screw terminals accept wire sizes from
16 gage to 22 gage. Twenty-gage wire is recommended for
high channel count applications. The 34905A and 34906A
RF Multiplexers use SMB connectors. A standard set of
(10) BNC-to-SMB adapter cables is provided with each
RF module for convenient BNC connections.

Multiplexer Actuator Matrix RF multiplexer Multifunction

34901A 34902A

General

Number of channels 20 + 2 16 40 20 4 x 8 Dual 1 x 4 See page 25

2/4 wire 2/4 wire 1 wire SPDT 2 wire 50 Ω 75 Ω
Connects to internal DMM
Scanning speed 60 ch/s 250 ch/s
Open/close speed 120/s 120/s 70/s 120/s 120/s 60/s

Input

Voltage (dc , ac rms)

[2]

Current (dc , ac rms) 1 A 50 mA 1 A 1 A 1 A 0.7 A
Power (W , VA) 50 W 2 W 50 W 50 W 50 W 20 W

DC characteristics

Offset voltage
Initial closed channel R

[3]

[3]

Isolation ch-ch, ch-earth > 10 GΩ > 10 GΩ > 10 GΩ > 10 GΩ > 10 GΩ > 1 GΩ

AC characteristics

Bandwidth

[4]

Insertion loss (dB) 10 MHz — — — — — -0.1 -0.1

100 MHz — — — — — -0.4 -0.4
500 MHz — — — — — -0.6 -0.5

1 GHz — — — — — -1 -1

1.5 GHz — — — — — -1.2 -1.5
2 GHz — — — — — -3 -2

SWR 0-9.99 MHz — — — — — 1.02 1.02

10-99.99 MHz — — — — — 1.05 1.05
100-499.99 MHz — — — — — 1.20 1.25
500-999.99 MHz — — — — — 1.20 1.40

1-1.499 GHz — — — — — 1.30 1.40

1.5-2 GHz — — — — — 1.40 2.00

[4]

ch-ch cross talk (dB)

10MHz -45 -45 -18

100 MHz — — — — — -85 -75
500 MHz — — — — — -65 -65

1 GHz — — — — — -55 -50

1.5 GHz — — — — — -45 -40
2 GHz — — — — — -35 -35

Risetime < 300 ps
Signal delay < 3 ns
Capacitance HI - LO < 50 pF < 50 pF < 50 pF < 10 pF < 50 pF < 20 pF

LO - Earth < 80 pF < 80 pF < 80 pF < 80 pF < 80 pF —

Volt-Hertz limit 10

Other

T/C cold junction accuracy

[3]

(typical) 0.8 °C 0.8 °C 0.8 °C

Switch life No load (typical) 100 M 100 M 100 M 100 M 100 M 5 M 5 M

Rated load (typical)

Temperature Operating all cards — 0 °C to 55 °C

Storage all cards — -20 °C to 70 °C

Humidity (non-condensing) all cards — 40 °C to 80% RH

[1] Not recommended for connection to ac line without external tran-

sient suppression. Up to 250 ch/s to internal memory. See scanning

rates for measurement condition and rate on each instrument.
[2] Channel-to-channel or channel-to-earth
[3] Errors included in DMM measurement accuracy specifi cations

●●●

300 V 300 V 300 V 300 V 300 V 42 V

< 3 uV < 6 uV < 3 uV < 3 uV < 3 uV < 6 uV

< 1 Ω < 1 Ω < 1 Ω < 0.2 Ω < 1 Ω < 0.5 Ω

10 MHz 10 MHz 10 MHz 10 MHz 10 MHz 2 GHz

8

[7]

100 k 100 k 100 k 100 k 100 k 100 k 100 k

[1]

34908A 34903A 34904A 34905A 34906A 34907A

for module

specifi cations

[1]

60 ch/s

[5]

[6]

8

10

8

10

[8]

-45 -33 -100 -85

8

10

8

10

10

10

2 GHz

[5]

[4] 50 Ω source, 50 Ω load
[5] Bandwidth direct to card SMB connectors
[6] Isolation within channel 1 to 20 or 21 to 40 banks is -40 dB
[7] Applies to resistive loads only
[8] Thermocouple measurements not recommended with 34908A

module due to common lo confi guration

20

Multiplexer selection guide

Backplane switches

Internal
DMM input

01

10

Com

H
L

H
L

H
L

H
L

H
L

H
L

I
L

I
L

I
L

I
L

H
L

H
L

T

Com
(4W sense)

11

20

21

Current
channels

22

Com
(Current)

Fuse

Fuse

Internal
DMM input
(4W sense)

Internal
DMM input
(Current)

Reference
junction
sensor

Channel switches

Bank switch

Shunt switches

Choose between the broad functionality of the 34901A, the
high speed scanning of the 34902A, or the single-ended
density of the 34908A. These three modules are the only
way to connect to the 34970A/34972A internal DMM. They
can be used to scan with external instruments as well.

All multiplexer modules employ break-before-make
scanning, ensuring only one closed channel (or channel
pair) at a time. Multiple channel closures are allowed on
the 34901A and 34902A modules when not configured
for scanning.

The 34908A does not allow multiple channel closures
at any time.

34901A

20-Channel General Purpose Multiplexer

• 60 ch/s scanning

• Two- and four-wire scanning

• Built-in thermocouple reference
junction

• 300 V switching

34901A 34902A 34908A

Number of channels 20 + 2 16 40
Max scan speed 60 ch/s 250 ch/s 60 ch/s
Number of contacts 2 or 4 2 or 4 1
Temperature

Thermocouple ● ● ●

2-wire RTD ● ● ●
4-wire RTD ● ●

Thermistor ● ● ●
dc Volts ● ● ●
ac Volts ● ● ●
2-wire Ohms ● ● ●
4-wire Ohms ● ●
Frequency ● ● ●
Period ● ● ●
dc current ●
ac current ●

The Agilent 34901A is the most
versatile multiplexer for general
purpose scanning. It combines
dense, multifunction switching with
60-channel/second scan rates to
address a broad spectrum of data
acquisition applications.

Two- and four-wire channels can
be mixed on the same module. Two
additional fused inputs (22 channels
total) route up to 1 A of current to
the internal DMM, allowing ac and dc
current measurements without the
need for external shunt resistors.

21

34902A

Backplane switches

Internal
DMM input

01

08

Com

Com
(4W sense)

09

16

Internal
DMM input
(4W sense)

Reference
junction
sensor

Channel switches

Bank switch

H
L

H
L

T

H
L

H
L

H
L

H
L
H
L

H
L

01

20

21

40

Com
Com

H

H

L

H

H

H
L

H

Channel switches

Backplane

switch

Bank switch

Internal
DMM input

Reference
junction
sensor

T

16-Channel High-Speed Multiplexer

• Scanning up to 250 ch/s

• Two- and four-wire scanning

• Built-in thermocouple reference
junction

The Agilent 34902A employs reed
relays to achieve scan rates up
to 250 channels per second. Use
this module for high-throughput
automated test applications as well
as high-speed data logging and
monitoring tasks.

Sixteen two-wire inputs switch up to
300 V. Two- and four-wire channels
may be mixed on the same module.
User provided shunt resistors are
required for current measurements.

Note: Not recommended for connection to ac line without
external transient suppression.

34908A

40-Channel Single-Ended Multiplexer

• 60 ch/s scanning

• Single-wire switching for common
low applications

• Built-in thermocouple reference
junction

Use the Agilent 34908A for the
greatest density in common low
applications, such as battery test,
component characterization, and
benchtop testing.

Each module switches 40 one-wire
inputs. All two-wire internal measure­ments except current are supported.
The module low connection is
isolated from earth and can float
up to 300 V.

22

Note: Thermocouples must be electrically isolated from each
other to avoid current loops and subsequent measurement errors.

34903A

01

20

NC
COM
NO

NC
COM
NO

20-Channel Actuator/General Purpose Switch

• SPDT (Form C) latching relays

• 300 V, 1 A actuation and control

This general purpose switch module has 20 independent
single-pole, double-throw (SPDT) relays. Use it to cycle
power to products under test, control indicator and status
lights, and to actuate external power relays and solenoids.
Combine it with matrix and multiplexer modules to build
custom switch systems. Its 300 V, 1 A contacts can handle
up to 50 W, enough for many power line switching applica­tions.

34904A

4x8 Two-wire Matrix Switch

• 32 two-wire crosspoints

• 300 V, 1 A switching

The Agilent 34904A gives you the most flexible connection
path between your device under test and your test equip­ment, allowing different instruments to be connected to
multiple points on your DUT at the same time.

Rows or columns may be connected between multiple
modules to build 8x8, 4x16 or larger matrices, with up to
96 crosspoints in a single frame.

Col 1

H L

Col 2

H L

Col 8

H L

H

Row 1

L

H

Row 2

L

H

Row 3

L

H

Row 4

L

H

L

H

Channel 31

L

(Row 3, Column 1)

23

34905A 50 Ω

0 dB

-1 dB

-2 dB

-3 dB

-4 dB

10 MHz 100 MHz 1 GHz 3 GHz

1.80

1.60

1.40

1.20

1.00

10 MHz 100 MHz 1 GHz 3 GHz

-20 dB

-40 dB

-60 dB

-80 dB

-100 dB

10 MHz 100 MHz 1 GHz 3 GHz

0 dB

-1 dB

-2 dB

-3 dB

-4 dB

10 MHz 100 MHz 1 GHz 3 GHz

1.80

1.60

1.40

1.20

1.00

-20 dB

-40 dB

-60 dB

-80 dB

-100 dB

34906A 75 Ω

Dual 4-Channel RF Multiplexers

• 2 GHz bandwidth

• BNC to SMB adapter cables included

The Agilent 34905A and 34906A RF multiplexers offer
broadband switching capabilities for high frequency and
pulsed signals. Use them to route test signals between
your device under test and your signal generator, oscillo­scope, spectrum analyzer, or other instrumentation.

The RF multiplexers are arranged as two independent
1x4 multiplexers, each with a common shield and a
switched center conductor. Connections can be made
directly to SMB inputs with 2 GHz usable bandwidth, or to
the BNC-to-SMB adapters provided with 1 GHz bandwidth.
Multiple banks may be cascaded together for applications
requiring even larger topologies—create a 16:1 multiplexer
in a single frame.

11

12

Com

13

14

21

22

Com

23

24

50 Ω MUX typical AC performance graphs

Insertion loss

VSWR

Crosstalk

75 Ω MUX typical AC performance graphs

Insertion loss VSWR Crosstalk

direct to card
using provided adapter cables

24

34907A

Port 1
Channel 01

Port 2
Channel 02

Channel 03

Channel 04

Channel 05

Bit 0

Bit 7

8

Bit 0

Bit 7

16

8

26 Bits

+IN

-IN

Gate
Gate

DIO

TOT

DAC 1

16

DAC 2

Multifunction Module

• 16 bits of digital input and output

• 100 kHz totalizer input

• Two ± 12 V analog outputs

The Agilent 34907A allows great flexibility for a variety
of sense and control applications. It combines two 8-bit
ports of digital input and output, a 100 kHz gated totalizer,
and two ± 12 V analog outputs—all on a single earth­referenced module. The digital inputs and totalizer input
may be included in a scan. Alarm limits for the digital and
event counter inputs are evaluated continuously, capturing
and logging alarm conditions even between scans.

Digital input/ouput

Use the digital outputs with an external power supply to
control microwave switches and attenuators, solenoids,
power relays, indicators, and more. Use the digital inputs
to sense limit switch and digital bus status. There are no
complex handshake modes; reads and writes are initiated
either from the front panel or the bus.

Port 1, 2 8 bit, input or output, nonisolated
Vin(L) < 0.8 V (TTL)
Vin(H) > 2.0 V (TTL)
Vout(L) < 0.8 V @ Iout = -400 mA
Vout(H) > 2.4 V @ Iout = 1 mA
Vin(H) max < 42 V with external open drain pull-up
Alarming Maskable pattern match or state

change
Speed 4 ms (max) alarm sampling
Latency 5 ms (typical) to 34970A alarm output
Read/Write Speed 95/s

Totalize input

Count events from devices like photo interrupters, limit
switches, and Hall-effect sensors.

It keeps an updated total which can be read via the front
panel or programmatically at any time. With 26 bits of
resolution, it can count events at full speed for nearly
11 minutes without an overflow.

Max count 2

26

- 1

Totalize input 100 kHz (max) Rising or falling edge,

programmable
Signal level 1 Vp-p (min) 42 Vpk (max)
Threshold 0 V or TTL, jumper selectable
Gate Input TTL-Hi, TTL-Lo, or none
Count reset Manual or Read + Reset
Read speed 85/s

Analog output

Use the two electronically calibrated analog outputs to
source bias voltages to your device under test, to control
your analog programmable power supplies, or use the
outputs as setpoints for your control systems. The outputs
are programmed directly in volts, either from the front panel
or from the bus.

DAC 1, 2 ± 12 V, nonisolated
Resolution 1 mV
IOUT 10 mA max
Settling time 1 ms to 0.01% of output
Accuracy ± (% of output + mV)
1 year ± 5 °C 0.25% + 20 mV
Temp. coefficient ± ( 0.015% + 1 mV)/°C

25

Rack mounting and dimensions

To rack mount a single instrument, order adapter kit 34190A.

To rack mount two instruments side-by-side, order 34191A 2U
dual fl ange kit and 34194A dual lock link kit.

To install one or two instruments in a sliding support shelf, order
shelf 5063-9255, and slide kit 1494-0015 (for single instrument, also
order fi ller panel 5002-3999).

26

Ordering Information

Mainframe

34970A Data Acquisition/Switch Unit with RS-232
and GPIB
34972A Data Acquisition/Switch Unit with LAN
and USB
Both mainframes include internal 6½ digit DMM, test
report, power cord, thermocouple, and screwdriver. Included
CD ROM has Agilent BenchLink DataLogger3 software,
IVI-COM and VXI PnP Drivers, Example Code Wizard,
Programmers Reference Help File, Users Guide, Quick
Start Tutorial and Service Guide. Modules are purchased
separately and are required to operate.

Accessories

11062A Kelvin Clip Set
34830A Benchlink Data Logger Pro Software optional

software package that adds limit checking
and decision making for more complex
applications

34307A 10-pack of J-type thermocouples
34308A 5-pack of 10 kΩ thermistors
34161A Accessory pouch
34131A Hard carrying case (transit case)
E5810A LAN/GPIB gateway for use with 34970A
82357B USB/GPIB converter for use with 34970A
34970-80010 DMM field installation kit. Fully calibrated

with test report and Quick Start kit

34905-60001 Kit of 10 SMB-to-BNC adapter cables, 50
34906-60001 Kit of 10 SMB-to-BNC adapter cables, 75 Ω

Ω

Option 001 Delete Internal DMM
Same as above but deletes DMM and Quick Start package.
Order 34970-80010 to retrofit DMM at a later time.

Option A6J ANSI Z540 compliant calibration
Option 0B0 Delete manual set
Option AB0 Taiwan: Chinese manual
Option AB1 Korea: Korean manual
Option AB2 China: Chinese manual
Option ABA English: English manual
Option ABD Germany: German manual
Option ABE Spain: Spanish manual
Option ABF France: French manual
Option ABJ Japan: Japanese manual
Option ABZ Italy: Italian manual

Modules

34901A 20-Channel armature multiplexer
34902A 16-Channel reed multiplexer
34903A 20-Channel actuator/general purpose switch
34904A 4 x 8 Two-wire matrix switch
34905A Dual 4-Channel RF multiplexer, 50 Ohms
34906A Dual 4-Channel RF multiplexer, 75 Ohms
34907A Multifunction module
34908A 40-Channel single-ended multiplexer

USB adaptors—If you need to bring your USB memory
port to the front panel you may consider a USB adapter
such as the USBAM-USBAM from VPI or the ECF504-UABS
from L-COM.

To find more application notes are product demos see the
product Web pages at:

www.agilent.com/find/34972A
www.agilent.com/find/34970A

27

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Revised: January 6, 2012

Product specifications and descriptions
in this document subject to change
without notice.

© Agilent Technologies, Inc. 2012
Published in USA, October 4, 2012
5965-5290EN