HP 34970a schematic

Service Gu ide

Publication Number 34970-90012 (order as 34970-90101 manual set) Edition 3, March 2003

For Safety information, Warranties, and Regulatory information, see the pages following the Index.

Note: The schematics for the 34970A are available as a separate downloadable PDF file from the Agilent web site at www.agilent. com.

Agilent 34970A Data Acquistion / S witch Unit

Note: Unless otherwise indicated, this manual applies to all serial numbers.

The Agilent Technologies 34970A combines precision measurement capability with flexible signal connections for your production and development test systems. Three module slots are built into the rear of the instrument to accept any combination of data acquisition or switching modules. The combination of data logging and data acquisition features makes this instrument a versatile solution for your testing requirements now and in the future.

Convenient Data Logging Features

• Direct measurement of thermocouples, RTDs, thermistors, dc voltage,

ac voltage, resistance, dc current, ac current, frequency, and period

• Interval scanning with storage of up to 50,000 time-stamped readings

• Independent channel configuration with function, Mx+B scaling,

and alarm limits available on a per-channel basis

• Intuitive user interface with knob for quick channel selection,

menu navigation, and data entry from the front panel

• Portable, ruggedized case with non-skid feet

• BenchLink Data Logger Software for Microsoft

Windows

included

Warning

Flexible Data Acquisition / Sw itching Features

• 6

⁄

-digit multimeter accuracy, stability, and noise rejection

• Up to 60 channels per instrument (120 single-ended channels)

• Reading rates up to 600 readings per second on a single channel and

scan rates up to 250 channels per second

• Choice of multiplexing, matrix, general-purpose Form C switching,

RF switching, digital I/O, totalize, and 16-bit analog output functions

• GPIB (IEEE-488) interface and RS-232 interface are standard

• SCPI (Standard Commands for Programmable Instruments) compatib ility

The procedures in this manual are intended for use by qualified, service-trained personnel only.

Agilent 34970A Data Acquisition / S witch Unit

The Front Panel at a Glance

Denotes a menu key. S e e th e n ex t p a g e f or d et a il s on me nu o pe ra tio n .

1 State Storage / Remote Interface Menus

2 Scan Start / Stop Key 3 Measurement Configuration Menu 4 Scaling Configuration Menu 5 Alarm / Alarm Output Configuration Menu 6 Scan-to-Scan Interval Menu 7 Scan List Single Step/Read Key

8 Advanced Measurement / Utility Menus 9 Low-Level Module Contr ol Keys 10 Single-Channel Monitor On/Off Key 11 View Scanned Data, Alarms, Errors Menu 12 Shift / Local Key 13 Knob 14 Navigation Arrow Keys

The Front-Panel Menus at a Glance

Several of the front-panel keys guide you through menus to configure various parameters of the instrument (see previous page). The following steps demonstrate the menu structure using the key.

1 Press the menu key. You are automatically guided to the first level of the menu. Rotate the knob to view the other choices on the first level of the menu.

The menu will automatically timeout after about 20 seconds of inactivity. You will be returned to the operation in progress prior to entering the menu.

2 Press the same menu key again to move to the next item of the menu. Typically, this is where you choose parameter values for the selected operation.

3 Rotate the knob to view the choices on this level of the menu. When you reach the end of the list, rotate the knob in the opposite direction to view all of the other choices.

The current selection is highlighted for emphasis. All other choices are dimmed.

4 Press the same menu key again to accept the change and exit the menu. A brief confirmation message is displayed.

Tip: To review the current configuration of a specific menu, press the menu key several times. A message

NO CHANGES is displayed when you exit the menu.

Display Annunciators

SCAN MON VIEW CONFIG

ADRS RMT ERROR EXT ONCE MEM LAST MIN MAX SHIFT 4W OC

Scan is in progress or enabled. Press and hold again to t urn of f . Monitor mode is enabled. Press again to turn off. Scanned readings, alarms, errors, or relay cycles are being viewed. Channel configuration is in progress on displayed channel. Measurement is in progress. Instrument is addressed to listen or talk over the remote interface. Instrument is in remote mode (remote interface). Hardware or remote interface errors are detected. Press to read err o r s . Instrument is configured for an external scan interval. Scan Once mode is enabled. Press t o initiat e and hold key to disable. Reading memory overflow; new readings will overwrite the oldest readings. Viewed data is the last reading stored during most recent scan. Viewed data is the minimum reading stored during most recent scan. Viewed data is the maximum reading stored during most recent scan.

has been pressed. Press again to turn off. 4-wire function is in use on displayed channel. Offset compensation is enabled on displayed channel. Alarms are enabled on displayed channel. Mx+B scaling is enabled on displayed channel. HI or LO alarm condition has occurred on indicated alarms.

To review the display annunciators, hold down the key as you turn on the instrument.

The Rear Panel at a Glance

WARNING

1 Slot Identifier (100, 200, 300)

2 Ext Trig Input / Alarm Outputs / Channel

Advance Input / Channel Closed Output (for pinouts, see chapter 4 in User’s Guide)

3 RS-232 Interface Connector

Use the Menu to:

• Select the GPIB or RS-232 interface (see chapter 2 in User’s Guide).

• Set the GPIB address (see chapter 2 in User’s Guide).

• Set the RS-232 baud rate, parity, and flow control mode (see chapter 2 in User’s Guide).

4 Power-Line Fuse-Holder Assembly 5 Power-Line Voltage Setting 6 Chassis Ground 7 GPIB (IEEE-488) Interface Connector

For protection from electrical shock, the power cord ground must not be defeated. If only a two-contact electrical outlet is available, connect the instrument’s chassis ground screw (see above) to a good earth ground.

The Plug-In Modules at a Glance

For complete specifications on each plug-in module, refer to the module sections in chapter 1.

34901A 20-Channel Armature Multiplexer

• 20 channels of 300 V switching

• Two channels for DC or AC current measurements (100 nA to 1 A)

• Built-in ther mocouple reference junction

• Switching speed of up to 60 channels per second

• Connects to the internal multimeter

Each of the 20 channels switches both fully isolated inputs to the internal multimeter. The module is divided into two banks of 10 two-wire channels each. When making four-wire resistance measurements, channels from Bank A are automatically paired with channels from Bank B. Two additional fused channels are included on the module (22 channels total) for making calibrated

AC current measurements with the internal multimeter (external shunt

resistors are not required). You can close multiple channels on this module only if you have not configured any channels to be part of the scan list. Otherwise, all channels on the module are break-before-make.

HI and LO inputs, thus providing

DC or

34902A 16-Channel Reed Multiplexer

• 16 channels of 300 V switching

• Built-in ther mocouple reference junction

• Switching speed of up to 250 channels per second

• Connects to the internal multimeter

Use this module for high-speed scanning and high-throughput automated test applications. Each of the 16 channels switches both

HI and LO inputs, thus providing fully isolated inputs to the internal

multimeter. The module is divided into two banks of eight two-wire channels each. When making four-wire resistance measurements, channels from Bank A are automatically paired with channels from Bank B. You can close multiple channels on this module only if you have not configured any channels to be part of the scan list. Other wise, al l channels on the module are break-before-make.

34903A 20-Channel Actuator / G eneral-Purpose Switch

• 300 V, 2 A actuation and switching

• SPDT (Form C) latching relays

• Breadboard area for custom circuits

Use this module for those applications that require high-integrity contacts or quality connections of non-multiplexed signals. This module can switch 300 V, 1 A (50 W maximum switch power) to your device under test or to actuate external devices. Screw terminals on the module provide access to the Normally-Open, Normally-Closed, and Common contacts for each of the 20 switches. A breadboard area is provided near the screw terminals to implement custom circuitry, such as simple filters, snubbers, or voltage dividers.

34904A 4x8 Two-Wire Matrix Switch

• 32 two-wire crosspoint s

• Any combination of inputs and outputs can be connected at a time

• 300 V, 1 A switching

Use this module to connect multiple instruments to multiple points on your device under test at the same time. You can connect rows and columns between multiple modules to build larger matrices such as 8x8 and 4x16, with up to 96 crosspoints in a single mainframe.

34905/6A Dual 4-Channel RF Multiplexers

• 34905A (50Ω ) / 34906A (75Ω )

• 2 GHz bandwidth with on-board SMB connections

• 1 GHz bandwidth with SMB-to-BNC adapter cables provided

These modules offer wideband switching capabilities for high frequency and pulsed signals. Each module is organized in two independent banks of 4-to-1 multiplexers. Both modules offer low crosstalk and excellent insertion loss performance. To create larger cascade multiple banks together. Only one channel in each bank may be closed at a time.

RF multiplexers, you can

34907A Multifunction Module

• Two 8-bit Digital Input/Output ports, 400 mA sink, 42 V open collector

• 100 kHz Totalize input with 28 bits of resolution

• Two 16-bit, ± 12 V Calibrated Analog Outputs

Use this module to sense status and control external devices such as solenoids, power relays, and microwave switches. For greater flexibility, you can read digital inputs and the count on the totalizer during a scan.

34908A 40-Channel Single-Ended Multiplexer

• 40 channels of 300 V single-ended (common LO) switching

• Built-in thermocouple isothermal reference junction

• Switching speed of up to 60 channels per second

• Connects to the internal multimeter

Use this module for high-density switching applications which require single-wire inputs with a common to ensure that only one relay is connected at any time.

LO. All relays are break-before-make

In This Book

Specifications Chapter 1 lists the technical specifications for the mainframe and plug-in modules.

Quick Start Chapter 2 helps you get familiar with a few of the instrument’s front-panel features.

Front-Panel Overview Chapter 3 introduces you to the front-panel menus and describes some of the instrument’s menu features.

Calibration Procedures Chapter 4 provides calibration, verification, and adjustment procedures for the instrument.

Theory of Operation Chapter 5 describes block and circuit level theory related to the operation the instrument.

Service Chapter 6 provides guidelines for returning your instrument to Agilent Technologies for servicing, or for servicing it yourself.

Replaceable Parts Chapter 7 contains detailed parts lists for the mainframe and plug-in modules.

Schematics Chapter 8 contains the instrument’s block diagram, schematics, disassembly drawings, and component locator drawings.

If you have questions relating to the operation of the 34970A, call 1-800-452-4844 in the United States, or contact your nearest Agilent Technologies Sales Office.

If your 34970A fails within three years of original purchase, Agilent will repair or replace it free of charge. Call 1-877-447-7278 and ask for “Express Exchange.”

Contents

Chapter 1 Specifications

DC, Resistance, and Temperature Accuracy Specifications 16 DC Measurement and Operating Characteristics 17 AC Accuracy Specifications 18 AC Measurement and Operating Characteristics 19 Measurement Rate s an d Sys t em Char a c ter i sti c s 20 Module Specifications 21 BenchLink Data Logger Soft ware Specifications 24 Product and Module Dimensions 25 To Calculate Total Measurement Error 26 Interpreting Internal DMM Specifications 28 Configuring for Highest Accuracy Measurements 31

Chapter 2 Quick Start

To Prepare the Instrument for Use 35 To Connect Wiring to a Module 36 To Set the Time and Date 38 To Configure a Measurement Channel 39 To Monitor a Single Ch an ne l 40 To Close a Channel 41 If the Instrument Does Not Turn On 42 To Adjust the Carrying Handle 44 To Rack Mount the Instrument 45

Chapter 3 Front-Panel Overview

Front-Panel Menu Reference 49 To Unsecure for Calibration 51 To Secure Against Cali br a tio n 51 To Change the Security Code 52 Error Messages 52 To Perform a Zero Adjustment 53 To Apply Mx+B Scaling to Measurements 54 To Read the Relay Cycle Count 55 To Read a Digital Input Port 56 To Write to a Digital Output Port 57 To Read the Totalizer Count 58 To Output a DC Voltage 59

Contents

Chapter 4 Calibration Procedures

Agilent Technologies Calibration Services 63 Calibration Interval 63 Adjustment is Recommended 63 Time Required for Calibration 64 Automating Calibration Procedures 64 Recommended Test Equipment 65 Input Connections 66 Calibration Security 67 To Unsecure the Instrument Without the Security Code 68 Calibration Message 69 Calibration C o unt 69 Calibration Pr ocedure 70 Aborting a Calibration in Progress 70 Test Considerations 71 Performance Verification Tests 72 Self-Test 73 Quick Performanc e Check 74 Performance Verification Tests 74 Internal DMM Verification Tests 75 Zero Offset Verification 75 Gain Verification 77 Optional AC Performance Verification Tests 80 Internal DMM Adj ustments 81 Zero Adjustment 81 Gain Adjustment 82 –10 Vdc Adjustment Pro cedure (Optional) 85 Plug-in Mo dule Test Consideration s 87 Relay Verification 88 Relay Cycle Count 88 34901A Relay Contact Resistan ce V eri fication (Optional) 89 34902A Relay Contact Resistan ce V eri fication (Optional) 96 34903A Relay Contact Resistan ce V eri fication (Optional) 101 34904A Relay Contact Resistan ce V eri fication (Optional) 102 34905A/06A Relay Contact Resistance Verification (Optional) 105 34908A Relay Contact Resistan ce V eri fication (Optional) 106 Thermocouple Reference Junction (Optional) 112 Thermocouple Reference Junction Verificati on 112 Thermocouple Reference Junction Adjustments 113 34907A Analog Ou tput 114 Analog Output Verification Test 114 Analog Output Adjustment 115

Contents

Chapter 5 Theory of Operation

System Block Diagram 119 Floating Logic 120 Memory 123 Earth-Referenced Logic 124 Power Supplies 125 Front Panel 127 Backplane 128 Analog Bus 128 Digital Bus 128 Internal DMM 129 DMM Block Diagram 129 Input 130 Input Amplifier 131 Ohms Current Source 133 AC Circuit 134 A-to-D Converter 136 Switch Modules 138 Switch Module Control 138 Relay Drivers 140 34901A 142 34902A 144 34903A 146 34904A 147 34905A/34906A 148 34908A 149 Multifunction Mo d ul e 151 Multifunction Control 151 Totalizer 153 Analog Output 154 Digital I/O 155

Chapter 6 Service

Operating Checklist 159 Is the instrument inope rat i v e? 159 Does the instrument fail self-test? 159 Is the Current measurement function inoperative? 159 Types of Service Available 160 Standard Repair Service (worldwide) 160 Express Exchange (U.S.A. only) 160 Repackaging for Shipment 161 Cleaning 161 Electrostatic Discharge (ESD) Precautions 162 Surface Mount Repair 162 To Replace the Power-Line Fuse 163

Contents

Chapter 6 Service (continued)

Troubleshoot i ng Hi nt s 163 Unit is Inoperative 163 Unit Reports Error 705 164 Isolating to an Assembly 164 Unit Fails Self-Test 164 Power Supplies 165 Self-Test Procedures 167 Power-On Self-Test 167 Complete Self-Test 167 Plug-in Module Self-Test 167 Self-Tests 168 Battery Check and Replacement 172 To Verify the Battery 173 To Replace the Battery 173 Disassembly 174 General Disassembly 175 Internal DMM Disassembly 176 Front-Panel Chassis Disassembly 177 Additional Disassembly 178 Plug-in Module Disassembly 179

Chapter 7 Replaceable Parts

Replaceable Parts 182 To Order Replaceable Parts 182 34970A Mainframe 183 34970-66501 Main PC Assembly (A1) 184 34970-66502 Front-Panel and Keyboard PC Asse mb ly (A2) 189 34970-66503 Backplane PC Assemb ly (A 3) 190 34970-66504 Internal DMM PC Assembly (A4) 191 34901A 20-Channel Multiplexer 196 34902A 16-Channel Multiplexer 200 34903A 20-Channel Actuator 202 34904A 4x8 Matrix 204 34905A/34906A RF Multiplexer 207 34907A Multifunction Modul e 209 34908A 40-Channel Multiplexer 213 Manufacturer’s List 216

Contents

Chapter 8 Schematics

Agilent 34970A System Block Diagram 221 A1 Component Locator (top) 222 A1 Component Locator (bottom) 223 A1 Power Supply Schematic (Sheet 1 of 4) 224 A1 Floating Logic Schematic (Sheet 2 of 4) 225 A1 Earth Referenced Logic Schematic (Sheet 3 of 4) 226 A1 Memory Schematic (Sheet 4 of 4) 227 A2 Component Locator 228 A2 Display and Keyboard Schematic 229 A3 Component Locator 230 A3 Backplane Schematic 231 A4 Component Locator (top) 232 A4 Component Locator (bottom) 233 A4 Input and Protection Schematic (Sheet 1 of 4) 234 A4 Input Amplifier and Ohms Cu rr en t Sch em ati c (Sheet 2 of 4) 235 A4 AC Schematic (Sheet 3 of 4) 236 A4 A/D Converter Schematic (Sheet 4 of 4) 237 34901A 20-Channel M ul tipl exe r Compo ne nt Loc a t or 238 34901A 20-Channel Multiplexer Schematic (Sheet 1 of 5) 239 34901A 20-Channel Multiplexer Schematic (Sheet 2 of 5) 240 34901A 20-Channel Multiplexer Schematic (Sheet 3 of 5) 241 34901A 20-Channel Multiplexer Schematic (Sheet 4 of 5) 242 34901A 20-Channel Multiplexer Schematic (Sheet 5 of 5) 243 34902A 16-Channel M ul tipl exe r Compo ne nt Loc a t or 244 34902A 16-Channel Multiplexer Schematic (Sheet 1 of 4) 245 34902A 16-Channel Multiplexer Schematic (Sheet 2 of 4) 246 34902A 16-Channel Multiplexer Schematic (Sheet 3 of 4) 247 34902A 16-Channel Multiplexer Schematic (Sheet 4 of 4) 248 34903A 20-Chann el Actu at o r Compo ne nt Locator 249 34903A 20-Channel Actuator Schematic (Sheet 1 of 3) 250 34903A 20-Channel Actuator Schematic (Sheet 2 of 3) 251 34903A 20-Channel Actuator Schematic (Sheet 3 of 3) 252 34904A 4x8 Matri x Compo ne nt Loc a tor 253 34904A 4x8 Matrix Schematic (Sheet 1 of 3) 254 34904A 4x8 Matrix Schematic (Sheet 2 of 3) 255 34904A 4x8 Matrix Schematic (Sheet 3 of 3) 256 34905A/34906A R F Mul t ipl exe r Co mpone nt Loc a tor 257 34905A/34906A RF Multiplexer Schematic (Sheet 1 of 2) 258 34905A/34906A RF Multiplexer Schematic (Sheet 2 of 2) 259 34907A Multifun c tio n Mo dul e Com p on en t Locato r 260 34907A Multifunction Modul e Sc hema t ic (S he et 1 of 5) 261 34907A Multifunction Modul e Sc hema t ic (S he et 2 of 5) 262 34907A Multifunction Modul e Sc hema t ic (S he et 3 of 5) 263 34907A Multifunction Modul e Sc hema t ic (S he et 4 of 5) 264 34907A Multifunction Modul e Sc hema t ic (S he et 5 of 5) 265 34908A 40-Channel M ul tipl exe r Compo ne nt Loc a t or 266 34908A 40-Channel Multiplexer Schematic (Sheet 1 of 3) 267 34908A 40-Channel Multiplexer Schematic (Sheet 2 of 3) 268 34908A 40-Channel Multiplexer Schematic (Sheet 3 of 3) 269

• DC, Resistance, and Temperature Accuracy Specifications, on page 16

• DC Measurement and Operating Characteristics, on page 17

• AC Accuracy Specifications, on page 18

• AC Measurement and Operating Characteristics, on page 19

• Measurement Rates and System Characteristics, on page 20

• Module Specifications:

34901A, 34902A, 34908A, 34903A, 34904A, on page 21 34905A, 34906A, on page 22 Typical AC Performance Graphs, on page 23 34907A, on page 24

• BenchLink Data Logger Software Specifications, on page 24

• Product and Module Dimensions, on page 25

• To Calculate Total Measurement Error, on page 26

• Interpreting Multimeter Specifications, on page 28

• Configuring for Highest Accuracy Measurements, on page 31

Specifications

Chapter 1 Specifications

DC, Resistance, and Temperature Accuracy Specifications

DC, Resistance, and Temperature Accura cy Specifications

± ( % of reading + % of range )

[1]

Includes measurement error, switching error, and transducer conversion error

Function Range

[3]

Test Current or Burden Voltage

DC Voltage 100.0000 mV

1.000000 V

10.00000 V

100.0000 V

300.000 V

Resistance

DC Current

34901A Only

Temperature Thermocouple

RTD R

[4]

[6]

100.0000 Ω

1.000000 kΩ

10.00000 kΩ

100.0000 kΩ

1.000000 MΩ

10.00000 MΩ

100.0000 MΩ

10.00000 mA

100.0000 mA

1.000000 A Type

B E

K N R S T

from 49Ω

to 2.1 kΩ

1 mA current source 1 mA 100 10

µA

5 500 nA 500 nA || 10 M

< 0.1 V burden < 0.6 V < 2 V

1100

-150

-100

-100 300 400

-100

-200°C to 600°C 0.06°C0.003°C

Thermistor 2.2 k, 5 k, 10 k -80

µA

Ω

Best Range Accuracy

°C to 1820°C °C to 1000°C

°C to 1200°C

°C to 1300°C °C to 1760°C °C to 1760°C

°C to 400°C

°C to 150°C 0.08°C0.002°C

[2]

24 Hour

23 °C ± 1 °C

0.0030 + 0.0035

0.0020 + 0.0006

0.0015 + 0.0004

0.0020 + 0.0006

0.0020 + 0.0020

0.0030 + 0.0035

0.0020 + 0.0006

0.0020 + 0.0005

0.002 + 0.00 1

0.015 + 0.00 1

0.300 + 0.01 0

0.005 + 0.010

0.010 + 0.004

0.050 + 0.006

[5]

1.2

°C

1.0

°C °C

1.0

°C

1.0

°C °C

1.2

°C

1.0

°C

90 Day

23 °C

± 5 °C

0.0040 + 0.0040

0.0030 + 0.0 00 7

0.0020 + 0.0 00 5

0.0035 + 0.0 00 6

0.0035 + 0.0 03 0

0.008 + 0.004

0.008 + 0.001

0.020 + 0.001

0.800 + 0.010

0.030 + 0.020

0.030 + 0.005

0.080 + 0.010

23 °C

0.0050 + 0.0040

0.0040 + 0.0 00 7

0.0035 + 0.0 00 5

0.0045 + 0.0 00 6

0.0045 + 0.0 03 0

0.010 + 0.004

0.010 + 0.001

0.040 + 0.001

0.800 + 0.010

0.050 + 0.020

0.050 + 0.005

0.100 + 0.010

Extended Range Accuracy

400

°C to 1100°C

-200

°C to -150°C

-210

-200

°C to -100°C

-200

°C to -100°C °C to 300°C

-50

°C to 400°C

-200

°C to -100°C

1 Year

± 5 °C

1.8

°C

1.5

°C °C

1.2

1.5

°C

1.5

°C °C

1.8

°C

1.5

°C

[5]

Temperature

Coefficient /°C

0 °C – 18 °C 28 °C – 55 °C

0.0005 + 0.0005

0.0005 + 0.0001

0.0005 + 0.0003

0.0006 + 0.0005

0.0006 + 0.0001

0.0010 + 0.0002

0.0030 + 0.0004

0.1500 + 0.0002

0.002 + 0.0020

0.002 + 0.0005

0.005 + 0.0010

0.03

°C

0.03

°C °C

0.03

°C

0.03

°C °C

0.03

°C

0.03

°C

⁄

[1] Specifications are for 1 hour warm up and 6 [2] Relative to calibration standards

digits

[3] 20% over range on all ranges except 300 Vdc and 1 Adc range s [4] Specifications 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.

[5] 1 year acc uracy. For total measurement accuracy, add tempe r ature probe error. [6] Thermocouple specifications not guaranteed when 34907A module is present

Chapter 1 Specifications

DC Measurement and Operating Characteristics

DC Measurement Characteristics

[1]

DC Voltage

Measurement Method:

Continuously Integrating, Multi-slope III A/D Converter

A/D Linearity :

0.00 02 % of reading + 0. 00 01 % of range Input Resistance: 100 mV, 1 V, 10 V ranges 100 V, 300 V ranges Input Bias Current: Input Protection:

Selectable 10 M

Ω or >10 GΩ

10 MΩ ±1% < 30 pA at 25

°C

300 V on all ranges

Resistance

Measurement Method: Offset Compensation:

Max. Lead Resistance: Input Protection:

Selectable 4-wi re or 2- wire O hms, Current source reference to LO input Selectable on 100

Ω, 1 kΩ, 10 kΩ ranges

10% of range per lead for 100 1 k

Ω ranges. 1 kΩ on all other range s

300 V on all ranges

DC Current

Shunt Resistance: Input Protection:

Ω for 10 mA, 100 mA; 0.1Ω for 1A.

1.5A 250 V fuse on 34901A module

Thermocouple

Conversion: Reference Junction Type: Open T/C Check:

ITS-90 software compensation Internal, Fixed, or External Selectable per channel. Open > 5 k

RTD α = 0.00385 (DIN ) and 0 . 00 391 Thermistor 44004, 44007, 44006 series Measurement Noise Rejection 60 Hz (5 0 Hz)

DC CMRR:

Integration Time

200 PLC / 3.33s (4s) 100 PLC / 1.67s (2s) 20 PLC / 333 ms (400 ms) 10 PLC / 167 ms (200 ms) 2 PLC / 33.3 ms (40 ms) 1 PLC / 16.7 ms (20 ms) < 1 PLC

140 dB Normal Mode Rejection

[4]

110 dB

[4]

105 dB

[4]

100 dB

[4]

95 dB 90 dB 60 dB 0 dB

[2]

[3]

Ω and

DC Operating Characteristics

[6]

Function

DCV, DCI, and Resistance:

Single Channel Measurement Rates Function

DCV, 2-Wire Ohms:

Thermocouple:

Digits

⁄

Resolution

⁄

(10 PLC)

⁄

(1 PLC)

⁄

(0.02 PLC)

0.1

°C (1 PLC)

[5]

Readings/s

0.6 (0.5) 6 (5)

60 (50)

300 600

[8]

Additional Noise Error

0% of range 0% of range

0.001% of range

0.01% of range

(0.02 PLC)

0.01

RTD, Thermistor:

0.1

°C (0.02 PLC)

°C (10 PLC)

°C (1 PLC)

Autozero OFF Operation

Following instrument warm-up at calibration temperature and < 10 minutes, add 0.0002% range additional error + 5

Ω

Settling Considerations

Reading settling times are affected by source impedance, low dielectric absorption characteristics, and input signal changes.

[1] 300 Vdc isolation voltage (ch-ch, c h-earth) [2] For 1 k [3] For power line frequency [4] For power line frequency For power line frequency [5] Reading speeds for 60 Hz and (50 Hz) operation; autozero OFF [6] 6 [7] Add 20

Ω unbalance in LO lead

⁄

digits=22 bits, 5

µV for DCV, 4 µA for DCI, or 20 mΩ for resistance

±0.1% ±1%, use 80 dB. ±3%, use 60 dB .

⁄

digits=18 bits, 4

⁄

digits=15 bits

[8] For fixed function and range, readings to memory, scaling and alarms off, autozero OFF

[7]

Readings/s

6 (5)

57 (47)

600

57 (47)

220

6 (5)

57 (47)

220

±1 °C

µV.

Chapter 1 Specifications

AC Accuracy Specifications

± ( % of reading + % of range )

[1]

Includes measurement error, switching error, and transducer conversion error

Function Range

[3]

Frequency

24 Hour

[2]

23 °C ± 1 °C

90 Day

23 °C

± 5 °C

1 Year

23 °C

± 5 °C

Temperature

Coefficient /°C

0 °C – 18 °C 28 °C – 55 °C

True RMS AC Voltage

Frequency and Period

True RMS AC Current

34901A Only

100.0000 mV

[4]

to 100 V

300.0000 V 3 Hz – 5 Hz

[6]

100 mV

300 V

10.00000 mA and

1.000000 A

100.0000 mA

3 Hz – 5 Hz 5 Hz – 10 Hz 10 Hz – 20 kHz 20 kHz – 50 kHz 50 kHz – 100 kHz 100 kHz – 300 kHz

5 Hz – 10 Hz 10 Hz – 20 kHz 20 kHz – 50 kHz 50 kHz – 100 kHz 100 kHz – 300 kHz

3 Hz – 5 Hz 5 Hz – 10 Hz 10 Hz – 40 Hz 40 Hz – 300 kHz

[4]

3 Hz – 5 Hz 5 Hz – 10 Hz

[4]

10 Hz – 5 kHz

[7]

3 Hz – 5 Hz 5 Hz – 10 Hz 10 Hz – 5 kHz

[5]

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 + 0.05

0.35 + 0.05

0.04 + 0.05

0.10 + 0.10

0.55 + 0.20

4.00 + 1.25

0.10

0.05

0.03

0.006

1.00 + 0.04

0.30 + 0.04

0.10 + 0.04

1.00 + 0.5

0.30 + 0.5

0.10 + 0.5

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 + 0.08

0.35 + 0.08

0.05 + 0.08

0.11 + 0.12

0.60 + 0.20

4.00 + 1.25

0.10

0.05

0.03

0.01

1.00 + 0.04

0.30 + 0.04

0.10 + 0.04

1.00 + 0.5

0.30 + 0.5

0.10 + 0.5

1.00 + 0.04

0.35 + 0.04

0.06 + 0.04

0.12 + 0.05

0.60 + 0.08

4.00 + 0.50

1.00 + 0.08

0.35 + 0.08

0.06 + 0.08

0.12 + 0.12

0.60 + 0.20

4.00 + 1.25

0.10

0.05

0.03

0.01

1.00 + 0.04

0.30 + 0.04

0.10 + 0.04

1.00 + 0.5

0.30 + 0.5

0.10 + 0.5

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 + 0.008

0.035 + 0.008

0.005 + 0.008

0.011 + 0.012

0.060 + 0.020

0.20 + 0.05

0.100 + 0.006

0.035 + 0.006

0.015 + 0.006

0.100 + 0.06

0.035 + 0.06

0.015 + 0.06

Additional Low Frequency Error for ACV, ACI (% of reading) Additional Error for Frequency, Period (% of reading)

Frequency

10 Hz - 20 Hz 20 Hz - 40 Hz 40 Hz - 100 Hz 100 Hz - 200 Hz 200 Hz - 1 kHz > 1 kHz

AC Filter

Slow

0 0 0 0 0 0

AC Filter

Medium

0.74

0.22

0.06

0.01

AC Filter

Fast

— —

0.73

0.22 0 0

0.18

Frequency

3 Hz - 5 Hz 5 Hz - 10 Hz 10 Hz - 40 Hz 40 Hz - 100 Hz 100 Hz - 300 Hz 300 Hz - 1 kHz > 1 kHz

⁄

Digits

0 0 0 0 0 0 0

⁄

Digits

0.12

0.17

0.2

0.06

0.03

0.01 0

⁄

Digits

0.12

0.17

0.2

0.21

0.07

0.02

0.005

0.001

[1] Specifications are for 1 hour warm up and 6 [2] Relative to calibration standards

⁄

digits, Slow ac filter

[3] 20% over range on all ranges except 300 Vac and 1 Aac 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 1x10

V Hz [6] Input > 100 mV. For 10 mV inputs, multiply % of reading error x 10. [7] Specified only for inputs > 10 mA

Chapter 1 Specifications

AC Measurement and Operating Characteristics

AC Measurement Characteristics

True RMS AC Voltage

Measurement Method:

AC-coupled True RMS – measures the ac component of input with up

[1]

to 300 Vdc of bias on any range Crest Factor : Additional Crest Factor Errors (non-sinewave):

Maximum 5:1 at Full Scale

[2]

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 AC Filter Bandwidth: Slow Medium Fast Input Impedance: Input Protection:

3 Hz – 300 kHz

20 Hz – 300 kHz

200 Hz – 300 kHz

1 M

Ω ± 2%, in parallel with 150 pF

300 Vrms on all ranges

Frequency and Period

Measurement Method: Voltage Rang es: Gate Time: Measurement Timeout:

True RMS AC Current

Measurement Method:

Reciprocal c ount i ng tec hni qu e

Same as AC Voltage function

1s, 100 ms, or 10 ms

Selectable 3 Hz, 20 Hz, 20 0 Hz LF li mit

Direct coupled to the fuse and

shunt. AC-coupled True RMS

measurement (measures the

ac component only)

Shunt Resistance: Input Protection:

Measurement Noi se Rejection

Ω for 10 mA; 0.1Ω for 100 mA, 1A

1.5A 250 V fuse on 34901A module

[3]

AC CMRR: 70 dB

Measurement Considerations (Frequency and Period)

All frequency counters are susceptible to error when measuring low-voltage, low-frequency signals. Shielding inputs from external noise pickup is critical for minimizing measurement errors.

AC Operating Characteristics

Function

ACV, ACI:

Single Channel Measurement Rates Function

ACV:

Frequency, Period:

[5]

Digits

⁄

2üxç31ç33 Çä 32é

Resolution

⁄

Slow (3 Hz)

⁄

Medium (20 Hz)

⁄

Fast (200 Hz)

⁄

2üxç31ç33 Çä 32é

⁄

Digits (1s gate)

⁄

Digits (1s gate)

⁄

Digits (100 ms)

⁄

Digits (100 ms)

⁄

Digits (10 ms)

⁄

Digits (10 ms)

[4]

Readings/s

7 sec/reading

[6]

[7]

100

[8]

[7]

AC Filter

Slow (3 Hz) Medium (20 Hz) Fast (200 Hz) Fast (200 Hz) Fast (200 Hz)

Readings/s

0.14 1 8

100

0.77 1

2.5 9

3.2

[1] 300 Vrms isolation voltage (ch-ch, ch-earth) [2] For frequencies below 100 Hz, slow AC filter specified for sinewave input only [3] For 1 k

Ω unbalance in LO lead

[4] Maximum reading rates for 0.01% of ac step additional error. Additional settling delay required when input dc level varies.

[5] 6

⁄

digits=22 bits, 5

[6] For external trigger or remote operation using default

⁄

digits=18 bits, 4

⁄

digits=15 bits

settling delay (Delay Auto) [7] Maximum limit with default settling delays defeated [8] For fixed function and range, readings to memory, scaling and alarms turned off

Chapter 1 Specifications

Measurement Rates and System Characteristics

Single Channel Meas ure me nt Rate s

Function

DCV, 2-Wire Ohms:

Thermocouple:

RTD, Thermistor:

ACV:

Frequency, Period:

System Speeds

INTO Memory

Single Channel DCV 34902A Scanning DCV 34907A Scanning Digital Input 34902A Scanning DCV, scaling and 1 alarm fail 34907A Scanning Totalize 34902A Scanning T emperature 34902A Scanning ACV 34902A Scanning DCV/Ohms, alternate channels 34901A/34908A Scanning DCV

Resolution

⁄

(10 PLC)

⁄

(1 PLC)

⁄

(0.02 PLC)

0.1

°C (1 PLC)

(0.02 PLC)

0.01

°C (10 PLC)

0.1

°C (1 PLC)

°C (0.02 PLC)

⁄

Slow (3 Hz)

⁄

Medium (20 Hz)

⁄

Fast (200 Hz)

[3]

⁄

Digits (1s gate)

⁄

Digits (100 ms)

⁄

Digits (10 ms)

[4]

[3]

[1] [2]

Readings/s

6 (5) 53 (47) 490

49 (47) 280

6 (5) 47 (47) 280

0.14 1 8 100

1 9 70

Ch/s

490 250 250 220 170 160 100

90 60

INTO and OUT of Memory to GPIB or RS-232 (INIT, FETCh)

34902A Scanning DCV 34902A Scanning DCV with Time stamp

OUT of Memory to GPIB

[5]

Readings Readings with Time stamp Readings with all Format Options ON

180 150

800 450 310

OUT of Memory to RS-232

Readings Readings with Time stamp Readings with all Format Options ON

600 320 230

DIRECT to GPIB or RS-232

Single Channel DCV 34902A Scanning DCV Single Channel MEAS DCV 10 or MEAS DCV 1 Single Channel MEAS DCV or MEAS OHMS

440 200

25 12

System Characteristics

Scan Triggering

Scan Count: Scan Interval: Channel Delay: External Trig Delay: External Trig Jitter:

Alarms

Alarm Outputs: Latency:

Memory

Readings: Time Stamp Resolution: Relative Absolute States: Alarm Queue:

General Specifications

Power Supply: Power Line Frequency: Power Consumption: Operating Environment:

Storage Environment: Weight (Mainframe): Safety: RFI and ESD: Warranty:

[1] Reading speeds for 60 Hz and (5 0 Hz) operation; autozero OFF [2] For fixed function and range, readings to memory, scaling and alarms off, autozero OFF [3] Maximum limit with default settling delays defeated [4] Speeds are for 4 Using 115 kbaud RS-232 setting. [5] Assumes relative time format (time since start of scan) [6] Storage at temperatures above 40

This ISM device complies with Cana dian ICES-001. Cet appareil ISM est conforme à la norme NMB-001

du Canada.

N10149

1 to 50,000 or continuous 0 to 99 hours; 1 ms step size 0 to 60 seconds/channel; 1 ms step size < 300

µs; With Monitor On, < 200 ms

< 2 ms

4 TTL compatible. Select able TTL l ogic HI or LO on Fail 5 ms (typical)

Battery Backed, 4 year typical life 50,000 readings

1 ms 1 s 5 instrument states Up to 20 events

100 V / 120 V / 220 V / 240 V 45 Hz to 66 Hz automatically sensed (12 W) 25 VA peak Full accuracy for 0 Full accuracy to 80% R.H. at 40

°C to 70 °C

-40

°C to 55 °C

[6]

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

⁄

digits, delay 0, display off, autozero off.

°C will decrease battery life

[6]

±10%

°C

Chapter 1 Specifications

Module Specifications

34901A, 34902A, 34908A, 34903A, 34904A

General 34901A

Number of Channels 20+2 16 40 20 4x8

2/4 wire 2/4 wire 1 wire SPDT 2 wire Connects to Internal DMM Yes Yes Yes No No Scanning Speed Open/Close Speed 120/s 120/s 70/s 120/s 120/s

Maximum Input

Voltage (dc, ac rms) 300 V 300 V 300 V 300 V 300 V Current (dc, ac rms ) 1 A 50 mA 1 A 1 A 1 A Power (W, VA) 50 W 2 W 50 W 50 W 50 W Isolation (ch-ch, ch-earth) dc, ac rms 300 V 300 V 300 V 300 V 300 V

DC Characteristi cs

Offset Voltage Initial Closed Channel R Isolation (ch-ch, ch-earth) > 10 GΩ > 10 GΩ > 10 GΩ > 10 GΩ > 10 GΩ

AC Characteristi cs

Bandwidth 10 MHz 10 MHz 10 MHz 10 MHz 10 MHz Ch-Ch Cross Talk (dB) Capacitance HI to LO < 50 pF < 50 pF < 50 pF < 10 pF < 50 pF Capacitance LO to Earth < 80 pF < 80 pF < 80 pF < 80 pF < 80 pF Volt-Hertz Limit

Other

T/C Cold Junction Accuracy Switch Life No Load (typical) 100M 100M 100M 100M 100M Switch Life Rated Load (typical) Temperature Operating All Modules – 0 Temperature Storage All Modules – -20 Humidity (non-condensing) All Modules – 40

[1]

[2]

[3]

10 MHz -45 -45 -18

60 ch/s 250 ch/s 60 ch/s

< 3 µV< 6 µV< 3 µV< 3 µV< 3 µV

< 1Ω < 1Ω < 1Ω < 0.2Ω < 1Ω

[2] [5]

(typical) 0.8 °C0.8 °C0.8 °C

[6]

100k 100k 100k 100k 100k

Multiplexer Actuator Matrix

34902A 34908A 34903A 34904A

[4]

108 108 108 108

[7]

°C to 55 °C

°C to 70 °C

°C / 80% R.H.

-45 -33

⁄

[1] Speeds are for 4 [2] Errors included in the DMM measurement accuracy specifications [3] 50

Ω source, 50Ω load

digits, delay 0, display off, autozero off. Using 115 kbaud RS-232 setting.

[4] Isolation within channel 1 to 20 or 21 to 40 banks is -40 dB [5] Thermocouple specifications not guaranteed when 34907A module is present [6] Applies to resistive loads only [7] Thermocouple measurements not recommended with 34908A module due to common LO configuration.

Chapter 1 Specifications

Module Specifications

34905A, 34906A

RF Multiplexer

General 34905A 34906A

Number of Channels Dual 1x4

Open/Close Speed 60/s

Maximum Input

Voltage (dc, ac rms) 42 V Current (dc, ac rms) 0.7 A Power (W, VA) 20 W

DC Characteristi cs

Offset Voltage Initial Closed Channel R Isolation (ch-ch, ch-earth) > 1 GΩ

Other

Switch Life No Load (typical) 5M Switch Life Rated Load (ty pical) Temperature Operating 0 Temperature Storage -20 Humidity (non-condensing) 40

[1]

[2]

Dual 1x4

Ω

< 6 µV

< 0.5Ω

100k

°C to 55 °C

°C to 70 °C

°C / 80% R.H.

Ω

The ac performance graphs are shown on the following page.

AC Characteristics 34905A 34906A

Bandwidth Insertion Loss (dB) 10 MHz -0.1 -0.1 100 MHz -0.4 -0.4 500 MHz -0.6 -0.5 1 GHz -1.0 -1.0

1.5 GHz -1.2 -1.5 2 GHz -3.0 -2.0 SWR 10 MHz 1.02 1.02 100 MHz 1.05 1.05 500 MHz 1.20 1.25 1 GHz 1.20 1.40

1.5 GHz 1.30 1.40 2 GHz 1.40 2.00 Ch-Ch Cross T a lk (dB) 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 to LO < 20 pF Volt-Hertz Limit 10

[3]

2 GHz 2 GHz

[4]

10 MHz -100 -85

[1] Errors included in DMM meas ur ement a ccur acy sp eci f ica tio ns [2] Applies to resistive loads only [3] Bandwidth direct to module SMB connectors [4] 50

Ω source, 50Ω load

Chapter 1 Specifications

Typical AC Performance Graphs

Typical AC Performanc e Gr aphs

34905A, 34906A

Insertion Loss (50Ω)

VSWR (50Ω)

Direct to Module Using provided adapter cables

Insertion Loss (75Ω)

VSWR (75Ω)

Crosstalk (50Ω)

Crosstalk (75Ω)

Chapter 1 Specifications

Module Specifications

34907A

Digital Input / Output

Port 1, 2:

in(L):

V V

in(H):

out(L): out(H):

in(H) Max:

V Alarming: Speed Latency Read/Write Speed:

Totalize Input

Maximum Count: Totalize Input:

Signal Level: Threshold:

Gate Input: Count Reset: Read Speed:

8 Bit, input or output, non-isolated < 0.8V (TTL) > 2.0V (TTL) < 0.8V @ Iout = - 400 mA > 2.4V @ Iout = 1 mA < 42V with extern al open dr ai n p ul l- up Maskable pat ter n ma tc h or st at e ch an ge 4 ms (max) alarm sampling 5 ms (typical) to 34970A alarm output 95/s

- 1 (67,108,863) 100 kHz (max), rising or falling edge, programmable 1 Vp-p (min) 42 Vpk (max) 0V or TTL, jumper selectable TTL-Hi, TTL-Lo, or none Manual or Read+Reset 85/s

Software Specifications

BenchLink Data Logge r

System Requirements

PC Hardware: Operating System:

Computer Interfaces

GPIB:

LAN-to-GPIB: RS-232 (Serial Port):

Performance

Scan and Save to Disk:

[1] Software provided on CD-ROM; includes utility to create floppy disks for installation [2] Interface and dr ive rs mus t be pu rch ase d a nd in st al le d se pa rat el y [3] 90 MHz Pentium

[3]

, 20 MB RAM

(not included with Option 001)

[1]

486, 66 MHz, 16 MB RAM, 12 MB disk space Windows Windows NT

[2]

Agilent 82335B, 82340A/B/C, 82341A/B/C/D National Inst r ument s A T-G PIB / TNT, PCI-GPIB Agilent E581 0A (Windows 98/Me/ NT/2000/XP Professional) PC COM 1 to 4

100 ch/s, 2 strip charts displayed

3.1, Windows 95,

4.0

Analog Voltage (DAC) Output

DAC 1, 2: Resolution: I

out:

Settling Time: Accuracy: 1 year Temp Coefficient:

[1] Limited to 40 mA total for all three slots (six DAC channels)

±5 °C

±12V, non-isolated (earth referenced)

1 mV 10 mA max 1 ms to 0.01% of output

±(% of output + mV)

0.25% + 20 mV

±(0.015% + 1 mV) / °C

[1]

Chapter 1 Specifications

Product and Module Dimensions

103.6 mm

254.4 mm

TOP

374.0 mm

88.5 mm

348.3 mm212.6 mm

Module

315.6

91.9

All dimensio ns are shown

in millimeters .

Chapter 1 Specifications

To Calculate Total Measurement Error

Each specification includes correction factors which account for errors present due to operational limitations of the internal explains these errors and shows how to apply them t o your measurements. Refer to “Interpreting Internal DMM Specifications,” starting on page 28, to get a better understanding of the terminology used and to help you interpret the internal

DMM’s specifications.

DMM. This section

The internal

DMM’s accuracy specifications are expressed in the form:

(% of reading + % of range). In addition to the reading error and range error, you may need to add additional errors for certain operating conditions. Check the li st below to mak e sure you inc lude all mea surement errors for a given function. Also, make sure you apply the conditions as described in the footnotes on the specification pages.

• If you are operating the internal DMM outside the 23 °C ± 5 °C

temperature range specified, apply an additional temperature coefficient error.

• For dc voltage, dc current, and resistance measurements, you may

need to apply an additional reading speed error.

• For ac voltage and ac current measurements, you may need to apply

an additional low frequency error or crest factor error.

Understanding the “ % of reading ” Error The reading error compensates for inaccur acies that result from the function and range you select, as well as the input signal level. The reading error varies according to the input level on the selected range. This error is expressed in percent of reading. The following table shows the reading error applied to the internal

Range Input Level

DMM’s 24-hour dc voltage specification.

Reading Error (% of reading)

Reading

Error Voltage

10 Vdc 10 Vdc 10 Vdc

10 Vdc

1 Vdc

0.1 Vdc

0.0015

≤ 150 µV

≤ 15 µV ≤ 1.5 µV

Chapter 1 Specifications

To Calculate Total Measurement Error

Understanding the “ % of range ” Error The range error compensates for inaccuracies that result from the function and range you select. The range error contributes a constant error, expressed as a percent of range, independent of the input signal level. The following table shows the range error applied to the

DMM’s 24-hour dc voltage specification.

Range Input Level

10 Vdc 10 Vdc 10 Vdc

10 Vdc

1 Vdc

0.1 Vdc

Range Error (% of range)

0.0004

Range

Error Voltage

≤ 40 µV ≤ 40 µV ≤ 40 µV

Total Measurement Error To compute the total measurement error, add the reading error and range error. You can then convert the total measurement error to a “percent of input” error or a “ppm (part-permillion) of input” error as shown below.

% of input error =

ppm of input error =

Example: Computing Total Measurement Error

Total Measurement Error

Input Signal Level

Total Measurement Error

Input Signal Level

× 100

× 1,000,000

Assume that a 5 Vdc signal is input to the DMM on the 10 Vdc range. Compute the total measurement error using the 90-day accuracy specification of

±(0.0020% of reading + 0.0005% of range).

Reading Error = 0.0020% x 5 Vdc = 100 Range Error = 0.0005% x 10 Vdc = 50 Total Error = 100

µV + 50 µV= ± 150 µV

± 0.0030% of 5 Vdc

± 30 ppm of 5 Vdc

µV

Chapter 1 Specifications

Interpreting Internal DMM Specifications

This section is provided to give you a better understanding of the terminology used and will help you interpret the internal specifications.

Number of Digits and Overrange

The “number of digits” specification is the most fundamental, and sometimes, the most confusing characteristic of a multimeter. The number of digits is equal to the maximum number of “9’s” the multimeter can measure or display. This indicates the number of full digits. Most multimeters have the ability to overrange and add a partial or “

⁄

” digit.

DMM’s

For example, the internal range. This represents six full digits of resolution. The internal

DMM can measure 9.99999 Vdc on the 10 V

DMM

can also overrange on the 10 V range and measure up to a maximum of

12.00000 Vdc. This corresponds to a 6

⁄

-digit measurement with 20%

overrange capability.

Sensitivity

Sensitivity is the minimum level that the multimeter can detect for a given measurement. Sensitivity defines the ability of the multimeter to respond to small changes in the input level. For example, suppose you are monitoring a 1 mVdc signal and you want to adjust the level to within measurement would require a multimeter with a sensitivity of at least 1 range. You could also use a 4

For ac voltage and ac current measurements, note that the smallest value that can be measured is different from the sensitivity. For the internal the selected range. For example, the internal to 1 mV on the 100 mV range.

±1 µV. To be able to respond to an adjustment this small, this

µV. You could use a 6

DMM, these functions are specified to measure down to 1% of

⁄

-digit multimeter if it has a 1 Vdc or smaller

⁄

-digit multimeter with a 10 mVdc range.

DMM can measure down

Chapter 1 Specifications

Interpreting Internal DMM Specifications

Resolution

Resolution is the numeric ratio of the maximum displayed value divided by the minimum displayed value on a selected range. Resolution is often expressed in percent, parts-per-million (ppm), counts, or bits. For example, a 6

⁄

-digit multimeter with 20% overrange capability can

display a measurement with up to 1,200,000 counts of resolution. This corresponds to about 0.0001% (1 ppm) of full scale, or 21 bits including the sign bit. All four specifications are equivalent.

Accuracy

Accuracy is a measure of the “exactness” to which the internal DMM’s measurement uncertainty can be determined relative to the calibration reference used. Absolute accuracy includes the Internal DMM’s relative accuracy specification plus the known error of the calibration reference relative to national standards (such as the U.S. National Institute of Standards and Technology ). To be meanin gful, th e accur acy specifica tion s must be accompanied with the conditions under which they are valid. These conditions should include temperature, humidity, and time.

There is no standard convention among multimeter manufacturers for the confidence limits at which specifications are set. The table below shows the probability of non-conformance for each specification with the given assumptions.

Specification

Criteria

Mean ± 2 sigma Mean ± 3 sigma

Probability

of Failure

4.5%

0.3%

Variations in performance from reading to reading, and instrument to instrument, decrease for increasing number of sigma for a given specification. This means that you can achieve greater actual measurement precision for a specific accuracy specification number. The 34970A is designed and tested to meet performance better than mean

±3 sigma of the published accuracy specifications.

Chapter 1 Specifications

Interpreting Internal DMM Specifications

24-Hour Accuracy

The 24-hour accuracy specification indicates the internal DMM’s relative accuracy over its full measurement range for s hort time intervals and within a stable environment. Short-term accuracy is usually specified for a 24-hour period and for a range.

±1 °C temperature

90-Day and 1-Year Accuracy

These long-term accuracy specifications are valid for a 23 °C ± 5 °C temperature range. These specifications include the initial calibration errors plus the internal DMM’s long-term drift errors.

Temperature Coefficients

Accuracy is usually specified for a 23 °C ± 5 °C 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 23 °C temperature range (the specification is per °C).

± 5 °C

Chapter 1 Specifications

Configuring for Highest Accuracy Measurements

The measurement configurations shown below assume that the internal

DMM is in its Factory 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 GΩ (for the 100 mV, 1 V,

and 10 V ranges) for the best dc voltage accuracy.

• Use 4-wire ohms and enable offset compensation for the best

resistance accuracy.

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.

Quick Start

One of the first things you will want to do with your instrument is to become acquainted with the front panel. We have written the exercises in this chapter to prepare the instrument for use and help you get familiar with some of its front-panel operations.

The front panel has several groups of keys to select various functions and operations. A few keys have a shifted function printed in blue below

the key. To perform a shifted function, press (the will turn on). Then, press the key that has the desired label below it.

For example, to select the Utility Menu, press .

SHIFT annunciator

If you accidentally press , just press it again to turn off the annunciator.

This chapter is divided into the following sections:

• To Prepare the Instrument for Use, on page 35

• To Connect Wiring to a Module, on page 36

• To Set the Time and Date, on page 38

• To Configure a Measurement Channel, on page 39

• To Monitor a Single Channel, on page 40

• To Close a Channel, on page 41

• If the Instrument Does Not Turn On, on page 42

• To Adjust the Carrying Handle, on page 44

• To Rack Mount the Instrument, on page 45

SHIFT

Chapter 2 Quick Start

To Prepare the Instrument for Use

1 Check the list of supplied items.

Verify that you have received the following items with your instrument. If anything is missing, contact your nearest Agilent Technologies Sales Office.

One power cord. One User’s Guide. This Service Guide. One Quick Reference Guide. Certificate of Calibration (if you ordered the internal DMM ). Quick Start Kit (if you ordered the internal DMM):

• One RS-232 cable.

• BenchLink Data Logger Software CD-ROM.

• One J-type thermocouple and a flatblade screwdriver.

Any plug-in modules that you ordered are delivered in a separate shipping container.

On/Standby Switch

WARNING

Note that this switch

Standby only.

is To disconnect the mains from the instrumen t , remove the power cord.

2 Connect the power cord and turn on the instrument.

The front-panel display will light up briefly while the instrument performs its power-on self-test. The

GPIB address is displayed.

The instrument initially powers up with all measurement channels turned off. To review the power-on display with all annunciators

turned on, hold down as you turn on the instrument. If the

instrument does not turn on properly, see page 42.

3Perform a complete self-test.

The complete self-test performs a more extensive set of tests than those performed at power-on. Hold down as you turn on the instrument

and hold down the ke y until you hear a long beep. The self-test will begin when you release the key f ollowing the beep.

Chapter 2 Quick Start

To Connect Wiring to a Module

1 Remove the module cov er.

3 Route wiring through strain relief.

Cable Tie Wrap

(optional)

2 Connect wiring to the screw terminals.

20 AWG

Typical

6 mm

4 Replace the module cover.

5 Install the module into mainframe.

Channel Number:

Slot Channel

Wiring Hints...

• For detailed information on each module, refer to the 34970A User’ s Guide.

• To reduce wear on the internal DMM relays, wire like functions on adjacent channels.

• Use shielded twisted pair Teflon insulated cables to reduce settling and noise errors.

• The diagrams on the next page show how to connect wiring to a multiplexer module for each measurement function.

Chapter 2 Quick Start

To Connect Wiring to a Module

Thermocouple

Thermocouple Types: B, E, J, K, N, R, S, T

2-Wire Ohms / RTD / Thermistor

Ranges: 100, 1 k, 10 k, 100 k, 1 M, 10 M, 100 MΩ RTD Types: 0.00385, 0.00391 Thermistor Types: 2.2 k, 5 k, 10 k

DC Voltage / AC Voltage / Frequency

Ranges: 100 mV, 1 V, 10 V, 100 V, 300 V

4-Wire Ohms / RTD

DC Current / AC Current

Valid only on channels 21 and 22 on the 34 9 0 1 A .

Ranges: 10 mA, 100 mA, 1A

Channel n (source) is automatically paired with Channel n+10 (sense) on the 34901A or Channel n+8 (sense) on the 34902A.

Ranges: 100, 1 k, 10 k, 100 k, 1 M, 10 M, 100 MΩ RTD Types: 0.00385, 0.00391

Chapter 2 Quick Start

To Set the Time and Date

All readings during a scan are automatically time stamped and stored in non-volatile memory. In addition, alarm data is time stamped and stored in a separate non-volatile memory queue.

Utility

1 Set the time of day.

Use and to select the field to modify and turn the knob to change the value. You can also edit the

AM/PM field.

TIME 03:45 PM

2 Set the date.

Use and to select the field to modify and turn the knob to change the value.

JUNE 01 2002

Chapter 2 Quick Start

To Configure a Measurement Channel

Use this general procedure to configure a measurement channel.

1 Select the channel.

Turn the knob until the desired channel is shown on the right side of front-panel display. The channel number is a three-digit number; the left-most digit represents the slot number (100, 200, or 300) and the two digits on the right indicate the channel number (102, 110, etc.).

Note: You can use and to skip to the beginning of the previous or next slot.

2 Select the measurement parameters for the selected channel.

Use the knob to scroll through the measurement choices on each level of the menu. When you press to make your selection, the menu

automatically guides you through all relevant choices to configure a measurement on the selected function. When you have finished configuring the parameters, you are automatically exited from the menu.

The present selection (or default) is displayed in full bright for easy identification. When you make a different selection, the new choice is shown in full bright and it becomes the default selection. The order of the choices always remains the same; however, you always enter the menu at the present (full-bright) setting for each parameter.

Note: The menu will timeout after about 20 seconds of inactivity and any changes made previously will take effect.

Chapter 2 Quick Start

To Monitor a Single Channel

You can use the Monitor function to continuously take readings on a single channel, even during a scan. This feature is used during front pa nel calibration procedures.

1 Select the channel to be monitored.

Only one channel can be monitored at a time but you can change the channel being monitored at any time by turning the knob.

2 Enable monitoring on the selected channel.

Any channel that can be “read” by the instrument can be monitored (the

MON annunciator turns on). This includes any combination of

temperature, voltage, resistance, current, frequency, or period measurements on multiplexer channels. You can also monitor a digital input port or the totalizer count on the multifunction module.

To disable monitoring, press again.

Chapter 2 Quick Start

To Close a Channel

On the multiplexer and switch modules, you can close and open individual relays on the module. However, note that if you have already configured

any multiplexer channels for scanning, you cannot independently close and open individual relays on that module.

1 Select the channel.

Turn the knob until the desired channel is shown on the right side of front-panel display. For this example, select channel 213.

2 Close the selected channel.

3 Open the selected channel.

Note: will sequentially open all channels on the module in the selected slot.

The table below shows the low-level control operations available for each of the plug-in modules.

Plug-In Module

34901A 20-Channel Mux ••• • 34902A 16-Channel Mux ••• • 34908A 40-Channel Single-Ended Mux 34903A 20-Channel Actuator •• 34904A 4x8 Matrix •• 34905A Dual 4-Channel RF Mux (50 34906A Dual 4-Channel RF Mux (75 34907A Multifunction Module (DIO) •• • 34907A Multifunction Module (Totalizer) •• 34907A Multifunction Module (DAC) •

[1]

••• •

[2]

Ω ) Ω )

[2]

•

[1] Only one channel can be closed at a time on this module. [2] Only one channel in each bank can be closed at a time on this module.

Chapter 2 Quick Start

If the Instrument Does Not Turn On

Use the following steps to help solve problems you might encounter when turning on the instrument.

1 Verify that there is ac power to the instrument.

First, verify that the power cord is firmly plugged into the power receptacle on the rear panel of the instrument. You should also make sure that the power source you plugged the instrument into is energized. Then, verify that the instrument is turned on.

The On/Standby switch is located on the lower left side of the front panel.

2 Verify the power-line voltage setting.

The line voltage is set to the proper value for your country when the instrument is shipped from the factory. Change the voltage setting if it is not correct. The settings are: 100, 120, 220, or 240 Vac.

Note: For 127 Vac operation, use the 120 Vac setting. For 230 Vac operation, use the 220 Vac setting.

See the next page if you need to change the line-voltage setting.

3 Verify that the power-line fuse is good.

The instrument is shi pped from th e factor y with a 500 m A fuse ins talled . This is the correct fuse for all line voltages.

See the next page if you need to replace the power-line fuse.

To replace the 500 mAT, 250 V fuse, order Agilent part number 2110-0458.

Chapter 2 Quick Start

If the Instrument Does Not Turn On

1 Remove the power cord. Remove the fuse-holder assembly from the rear panel.

3 Rotate the line-voltage selector until the

corr ect voltage appears in the window.

2 Remove the line-voltage selector from

the assembly.

Fuse: 500 mAT (for all line voltages) Agilent Part Number: 2110-0458

4 Replace the fuse-holder assembly in the rear panel.

100, 120 (127), 220 (230) or 240 Vac

Verify that the correct line voltage is selected and the power-line fuse is good.

Chapter 2 Quick Start

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.

Carrying PositionBenchtop Viewing Positions

Chapter 2 Quick Start

To Rack Mount the Instrument

You can mount the instrument in a standard 19-inch rack cabinet using one of three optional kits available. Instructions and mounting hardware are included with each rack-mounting kit. Any System II instrument of the same size can be rack-mounted beside the 34970A.

Remove the carrying handle, and the front and rear rubber bumpers, before rack-mounting the instrument.

To remove the handle, rotate it to the vertical p osition an d pull t he ends outward.

Front Rear (bottom view)

To remove the rubber bumper, stretch a corner and then slide it off.

Chapter 2 Quick Start

To Rack Mount the Instrument

To rack mount a single instrument, order adapter kit 5063-9240.

To rack mount two instruments side-by-side, order lock-link kit 5061-9694 and flange kit 5063-9212. Be sure to use the support rails inside the rack cabinet.

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

Front-Panel Overview

This chapter introduces you to the front-panel keys and menu operation. This chapter does not give a detailed description of every front-panel key or menu operation. It does, however, give you a good overview of the front-panel menu and many front-panel operations. See the Agilent 34970A User’s Guide for a complete discussion of the instrument’s capabilities and operation.

This chapter is divided into the following sections:

• Front-Panel Menu Reference, on page 49

• To Unsecure for Calibration, on page 51

• To Secure Against Calibration, on page 51

• To Change the Security Code, on page 52

• Error Messages, on page 52

• To Perform a Zero Adjustment, on page 53

• To Apply Mx+B Scaling to Measurements, on page 54

• To Read the Relay Cycle Count, on page 55

• To Read a Digital Input Port, on page 56

• To Write to a Digital Output Port, on page 57

• To Read the Totalizer Count, on page 58

• To Output a DC Vo ltage, on page 59

Chapter 3 Front-Panel Overview

Front-Panel Menu Reference

This section gives an overview of the front-panel menus. The menus are designed to automatically guide you through all parameters required to configure a particular function or operation. The remainder of this chapter shows examples of using the front-panel menus.

Configure th e measurement parameters on the displayed ch annel.

• Select measure me nt function (dc volts, oh ms, etc.) on the displaye d channel.

• Select transducer type for temperature measurements.

• Select units (°C, °F, or K) for temperature measurements.

• Select measureme nt rang e or au to ran ge .

• Select measureme nt resolution.

• Copy and paste measurement configuration to other ch an ne ls .

Configure the scaling parameters for the displayed channel.

• Set the gain (“M”) and offset (“B”) value for the displayed channel.

• Make a null measurement and store it as the offset value.

• Specify a custom la be l (RPM, PSI, etc.) for the displa ye d ch annel.

Configure al arms on the displayed channel.

• Select one of fou r ala rms to report alarm condit io ns on th e di sp la yed channel.

• Configure a hi gh lim it , lo w lim it , or bo th for the displayed chan ne l.

• Configure a bit pattern which will generate an alarm (for digital input channels).

Configure the four Alarm Outp ut ha rdw a re li ne s.

• Clear the state of the four alarm output lines.

• Select the “Latch” or “Track” mode for the four alarm output lines.

• Select the slope (ris in g or fa ll ing edge) for the four alarm out pu t lines.

Configure the event or action that controls the scan interval.

• Select the scan int erv al mod e (in te rva l, manual, external, or al arm) .

• Select the scan cou nt.

Chapter 3 Front-Panel Overview

Front-Panel Menu Reference

Configure the advanced measurement features on displayed channel.

• Set the integration time for measurements on the displayed channel.

• Set the channel-to-channel delay for scanning.

• Enable/disabl e th e th erm oc ou pl e ch ec k fe ature (T/C measurement s only ).

• Select the refere nce ju nc ti on source (T/C measurement s on ly ).

• Set the low frequency limit (ac m easurements only).

• Enable/disable offset compensation (resistance measurements only).

• Select the binary or decimal mode for digital operations (34907A on ly ).

• Configure the to ta lizer reset mode (total iz er on ly ).

• Select which edge is detected (rising or falling) for totalizer operations.

Configure system-related instrument parameters.

• Set the real-time system clock and calendar.

• Query the firmware revisions for the mainframe and installed modules.

• Select the inst rumen t ’ s pow er-o n co nf ig uration (last or factory rese t).

• Enable/disable the internal DMM.

• Secure/unsecure the instrument for calibration.

View readings, alarms, and errors.

• View the last 100 sc anned readings from memo ry (last, min, max, and av era ge ).

• View the first 20 alarms in the alarm queue (reading and time alarm occurred).

• View up to 10 errors in the error queue.

• Read the number of cycles for the disp layed relay (relay maintenance feature).

Store and recall in stru me nt sta tes.

• Store up to five inst rument states in non-volatile memory.

• Assign a name to ea ch storage location.

• Recall stored st ates, power-down state , factory reset state, or pr es et sta te .

Configure the remote interfa ce .

• Select the GPIB addre ss.

• Configure the RS -23 2 in te rfa ce (bau d rat e, pari ty , an d fl ow co ntrol).

Chapter 3 Front-Panel Overview

To Unsecure for Calibration

You can unsecure the instrument either from the front panel or over the remote interface. The instrument is secured when shipped from the factory and the security code is set to “

HP034970”.

• Once you enter a security code, that code must be used for both

front-panel and remote operation. For example if you secure the instrument from the front panel, you must use that same code to unsecure it from the remote interface.

• Press to enter the Utility menu.

When you first enter the Utility menu, the calibration entries toggle between

instrument, select correct security code, press again. When you return to the menu,

you will see new choices Note: If you enter the wrong secure code,

and a new choice,

CAL SECURED and UNSECURE CAL. To unsecure the

UNSECURE CAL and press . After entering the

CAL UNSECURED and SECURE CAL.

NO MATCH is displayed

EXIT, is shown.

To Secure Against Calibration

You can secure the instrument either from the front panel or over the remote interface. The instrument is secured when shipped from the factory and the security code is set to “

• Once you enter a security code, that code must be used for both

front-panel and remote operation. For example if you secure the instrument from the front panel, you must use that same code to unsecure it from the remote interface.

HP034970”.

• Press to enter the Utility menu.

When you enter the Utility menu, the calibration entries toggle between

instrument, select desired security code, press again. When you return to the

menu, you will see new choices

CAL UNSECURED and SECURE CAL. To secure the

SECURE CAL and press . After entering the

CAL SECURED and UNSECURE CAL.

Chapter 3 Front-Panel Overview

To Change the Security Code

• To change the security code, you must first unsecure the instrument,

and then enter a new code. Make sure you have read the security code rules described on page 67 before attempting to change the security code.

• To change the security code, first make sure that the instrument is

unsecured. Go to the and press (the instrument is now secured with the new code).

Changing the code from the front panel also changes the code as seen from the remote interface.

SECURE CAL entry, enter the new security code,

Error Messages

Error messages are retrieved in a first-in first-out (FIFO) order. When the ERROR annunciator is on, press to view error

messages. Use the arrow keys to scroll the message in the display. A list of the self-test errors messages and their meanings begin on

page 168. For a complete list of error messages and descriptions, see chapter 6 in

the 34970A User’s Guide.

Chapter 3 Front-Panel Overview

To Perform a Zero Adjustment

The instrument features closed case electronic calibration. No internal mechanical adjustments are required. The instrument calculates correction factors based upon an input reference value an d stores the correction factors in non-volatile memory. This procedure demonstrates making the zero adjustment from the front panel. The gain adjustments are similar.

DO NOT perform this procedure before reading Chapter 4. Chapter 4 describes this procedure, the required input connections, input signals, and test considerations required for a valid adjustment.

1 Configure the channel.

You must configure a channel before applying performing the adjustment procedure. Configure the ch annel to DC VOLTS

and 6

⁄

digits.

2 Apply the input signal

In this example, the input signal is a copper short (see page 66).

3 Setup the calibration.

The display will show PERFORM CAL..

4 Set the adjustment value.

The display will show the a number. Edit the number to the actual input value. For the Zero Adjustment, the input value is 0.000000.

+000.000,000 mVDC

5 Begin the adjustment.

The display will show the progress of the adjustment. When all the adjustments are completed, the display will show done.

DONE

Chapter 3 Front-Panel Overview

To Apply Mx+B Scaling to Measurements

To Apply Mx+B S caling to Measure ments

The scaling function all ows you to apply a gain and offset to all readings on a specified multiplexer channel during a scan. In addition to setting the gain (“M”) and offset (“B”) values, you can also specify a custom measurement label for your scaled readings (

1 Configure the channel.

You must configure the channel (function, transducer type, etc.) before applying any scaling values. If you change the measurement configuration, scaling is turned off on that channel and the gain and offset values are reset (M=1 and B=0).

2 Set the gain and offset values.

The scaling values are stored in non-volatile memory for the specified channels. A Factory Reset turns off scaling and clears the scaling values on all channels. An Instrument Preset or Card Reset does not clear the scaling values and does not turn off scaling.

RPM, PSI, etc.).

+1.000,000

-0.700,000 OHM

3 Select the custom label.

You can specify an optional three-character label for your scaled readings ( unit for the selected function (

LABEL AS OHM

4 Scaling is now applied to the measurements.

RPM, PSI, etc.). The default label is the standard engineering

Set Gain

Set Offset

VDC, OHM, etc.).

Chapter 3 Front-Panel Overview

To Read the Relay Cycle Count

The instrument has a Relay Maintenance System to help you predict relay end-of-life. The instrument counts the cycles on each relay in the instrument and stores the total count in non-volatile memory on each switch module. You can use this feature on any of the relay modules and the internal

• In addition to the channel relays, you can also query the count on

backplane relays and bank relays. Note that you cannot control the state of these relays from the front panel but you can query the count.

• You can also query the state of the three relays on the internal DMM.

These relays are numbered “1”, “2”, and “3” (which correspond to relays K102, K103, and K104 respectively). These relays open or close when a function or range is changed on a module.

• The 34908A multiplexer c ontain s 40 cha nnels whic h are swit ched

(

HI only) using only 20 relays. Each relay is used to switch HI on two

different channels (and only one channel can be closed at a time). The channels are arranged such that channels 01 and 21 use di fferent contacts on the same relay . The remain ing cha nnels ar e also pair ed in the same manner (channels 02 and 22, channels 03 and 23, etc.). Therefore, when you query the relay count on a cha nnel, the number reflects the number of times that the relay was closed. For example, the relay count will al ways be the same on channel s 01 and 21 .

DMM.

• For more information on relay life and load considerations, refer to

“Relay Life and Preventative Maintenance” in the 34970A User’s Guide.

• To read the count on the active channel, choose the following item

and then turn the knob. To read the count on the internal relays, turn the knob counterclockwise beyond the lowest numbered channel in the instrument. To read the “hidden” relays, turn the knob clockwise beyond the highest numbered channel in the current slot.

RELAY CYCLES

DMM

Chapter 3 Front-Panel Overview

To Read a Digital Input Port

The multifunction module (34907A) has two non-isolated 8-bit input/output ports which you can use for reading digital patterns. You can read the live status of the bits on the port or you can configure a scan to include a digital read.

1 Select the Digital Input port.

Select the slot containing the multifunction module and continue turning the knob until

2 Read the specified port.

You can specify whether you want to use binary or decimal format. Once you have selected the number base, it is used for all input or output operations on the same port. To change the number base,

press the key and select

DIN is displayed (channel 01 or 02).

USE BINARY or USE DECIMAL.

01010101 DIN

Bit 7 Bit 0

Binary Display Shown

The bit pattern read from the port will be displayed until you press another key, turn the knob, or until the display times out.

Note: To add a digital input channel to a scan list, press and select the

DIO READ choice.

Chapter 3 Front-Panel Overview

To Write to a Digital Output Port

The multifunction module (34907A) has two non-isolated 8-bit input/output ports which you can use for outputting digital patterns.

1 Select the Digital Output port.

Select the slot containing the multifunction module and continue turning the knob until

2 Enter the bit pattern editor.

Notice that the port is now converted to an output port (

00000000 DOUT

Bit 7 Bit 0

3 Edit the bit pattern.

Use the knob and or keys to edit the individu al bit values. You can specify whether you want to use binary or decimal format. Once you have selected the number base, it is used for all input or output operations on the same port. To change the number base,

press the key and select

240 DOUT

DIN is displayed (channel 01 or 02).

DOUT).

Binary Display Shown

USE BINARY or USE DECIMAL.

Decimal Display Shown

4 Output the bit pattern to the specified port.

The specified bit pattern is latched on the specified port. To cancel an output operation in progress, wait for the display to time out.

Chapter 3 Front-Panel Overview

To Read the Totalizer Count

The multifunction module (34907A) has a 26-bit totalizer which can count

TTL pulses at a 100 kHz rate. You can manually read the totalizer

count or you can configure a scan to read the count.

1 Select the totalizer c h a n nel .

Select the slot containing the multifunction module and continue turning the knob until

2 Configure the totalize mode.

The internal count starts as soon as you turn on the instrument. You can configure the totalizer to reset the count to “0” after being read or it can count continuously and be manually reset.

READ + RESET

TOTALIZE (channel 03) is displayed.

3 Read the count.

The count is read once each time you press ; the count does not update automatically on the display. As configured in this example, the count is automatically reset to “0” each time you read it.

12345 TOT

The count will be displayed until you press another key, turn the knob, or until the display times out. To manually reset the totalizer count,

press .

Note: To add a totalizer channel to a scan list , press and select the

TOT READ choice.

Chapter 3 Front-Panel Overview

To Output a DC Volta ge

To Output a DC Voltage

The multifunction module (34907A) has two analog outputs capable of outputting calibrated voltages between

±12 volts.

1Select a

Select the slot containing the multifunction module and continue turning the knob until

2 Enter the output voltage editor.

+00.000 V DAC

3 Set the desired output voltage.

Use the knob a nd or keys to edit the individual digits.

+05.250 V DAC

4 Output the voltage from the se l ec t ed

The output voltage will be displayed until you press another key or turn the knob. To manually reset the output voltage to 0 volts, press .

DAC Output channel.

DAC is displayed (channel 04 or 05).

DAC.

Calibration Procedures

This chapter contains procedures for verification of the instrument’s performance and adjustment (calibration). These procedures are required only if the internal DMM is installed. The chapter is divided into the following sections:

• Agilent Technologies Calibration Services, on page 63

• Calibration Interval, on page 63

• Time Required for Calibration, on page 64

• Automating Calibration Procedures, on page 64

• Recommended Test Equipment, on page 65

• Input connections, on page 66

• Calibration Security, on page 67

• Calibration Message, on page 69

• Calibration Count, on page 69

• Calibration Procedures, on page 70

• Aborting a Calibration in Progress, on page 70

• Test Considerations, on page 71

• Performance Verification Tests, on page 72

• Internal DMM Verification Tests, o n page 75

• Optional AC Performance Verification Tests, on page 80

• Internal DMM Adjustments, on page 81

• –10 Vdc Adjustment Procedure (Optional), on page 85

• Plug-in Module Test Considerations, on page 87

• Relay Verification, on page 88

• Thermocouple Reference Junction (Optional), on page 112

• 34907A Analog Output, on page 114

Closed-Case Electronic Calibration The instrument feature s closed-case electronic calibration. No internal mechanical adjustments are required. The instrument calculates correction factors based upon the input reference value you set. The new correction factors are stored in non-volatile memory until the next calibration adjustment is performed. Non-volatile EEPROM calibration memory does not change when power has bee n off or after a remote interface reset.

Chapter 4 Calibration Procedures

Agilent Technologies Calibration Services

When your instrument is due for calibration, contact your local Agilent Service Center for a low-cost recalibration. The 34970A is supported on automated calibration systems which allow Agilent to provide this service at competitive prices.

Calibration Interval

The instrument should be calibrated on a regular interval determined by the measurement accuracy requirements of your application. A 1-year interval is adequate for most applications. Accuracy specifications are warranted only if adjustment is made at regular calibration intervals. Accuracy specifications are not warranted beyond the 1-year calibration interval. Agilent does not recommend extending calibration intervals beyond 2 years for any application.

Adjustment is Re c om m e nd e d

Whatever calibration int erval you select, Agilent recommends that complete re-adjustment should always be performed at the calibration interval. This will assure that the 34970A will remain within specification for the next calibration interval. This criteria for re-adjustment provides the best long-term stability. Performance data measured using this method can be used to extend future calibration intervals.

Use the Calibration Count feature (see page 69) to verify that all adjustments have been performed.

Chapter 4 Calibration Procedures

Time Required for Calibration

The 34970A can be automatically calibrated under computer control. With computer control you can perform the comple te calibration procedure and performance verification tests in less than 30 minutes once the instrument is warmed-up (see “Test Considerations” on page 71). Manual calibrations using the recommended test equipment will take approximately 2 hours.

Automating Calibration Procedures

You can automate the complete verification and adjustment procedures outlined in this chapter if you have access to programmable test equipment. You can program the instrument configurations specified for each test over the remote interface. You can then enter readback verification data into a test program and compare the results to the appropriate test limit values.

You can also adjust the instrument from the remote interface. Remote adjustment is similar to the local front-panel procedure. You can use a computer to perform the adjustment by first selecting the required function and range. The calibration value is sent to the instrument and then the calibration is initiated over the remote interface. The instrument must be unsecured prior to initiating the calibration procedure.

For further information on programming the instrument, see chapter 5 in the 34970A User’s Guide.

Chapter 4 Calibration Procedures

Recommended Test Equipment

The test equipment recommended for the performance verification and adjustment procedures is listed below. If the exact instrument is not available, substitute calibration standards of equivalent accuracy.

A suggested alternate method would be to use the Agilent 3458A 8 digit Digital Multimeter to measure less accurate yet stable sources. The output value measured from the source can be entered into the instrument as the target calibration value.

Application Recommended Equipment Accuracy Requirements

Zero Calibration DC Voltage DC Current Resistance AC Voltage AC Current Frequency Analog Output

34907A Thermocouple

Reference Junction 34901A 34902A 34908A

Relay contact resistance All switch modu le s

[1]

[1] In addition to the internal DMM, these applications require an input multiplexer module. The 34901A is recommended. [2] Thermistor YSI 44031 is available as Agilent part number 34308A (package of five).

None 4 -terminal all copper short Fluke 5700A <1/5 instrument 24 hour spec Fluke 5700A/ 57 25A <1/5 instrument 24 hour spec Fluke 5700A <1/5 instrument 24 hour spec Fluke 5700A/ 57 25A <1/5 instrument 24 hour spec Fluke 5700A/ 57 25A <1/5 instrument 24 hour spec Agilent 33220A <1/5 instrumen t 24 hou r spe c Agilent 34401A <1/5 instrumen t 24 hou r spe c

Thermistor YSI 4403 1 (tw o ) J Type Calibrated Thermocouple

Triple Point Cell

Agilent 34401A

[2]

± 0.1 °C

± 0.001Ω resolution

⁄

Chapter 4 Calibration Procedures

Input Connections

You will need an input multiplexer module to verify or adjust the internal DMM. Input connections can be made using a 34901A 20-Channel Multiplexer.

To use a 34901A to completely verify and adjust the internal DMM, make the following connections:

34901A

Connections for DC/AC Current

Note: Use shielded twisted pair Teflon and noise errors. Connect the shield to the source LO output.

Connections for 4-wire Ohms

Connections for DC V, AC V, 2- and 4-wire Ohms

Copper Short



insulated cables to reduce settling

To Calibrator

You can also use a 34902A for test and adjustment of voltage, frequency , and resistance function s. You cannot test or adjust current inputs with a 34902A. If you use a 34902A; connect the copper shorts to Channels 7 and 15 and make the input connections to Channels 8 and 16.

Teflon® is a registered trademark of E.I. du Pont de Nemours and Company.

Chapter 4 Calibration Procedures

Calibration Security

This feature allows you to enter a security code to prevent accidental or unauthorized adjustments of the instrument. When you first receive your instrument, it is secured. Before you can adjust the instrument, you must unsecure it by entering the correct security code.

See page 51 in Chapter 3 for a procedure to enter the security code.

• The security code is set to “HP034970” when the instrument is

shipped from the factory. The security code is stored in non-volatile memory, and does not change when power has been off, after a Factory Reset (*RST command), or after an Instrument Preset (SYSTem:PRESet command).

• The security code may contain up to 12 alphanumeric characters.

The first character must be a letter, but the remaining characters can be letters, numbers, or an underscore ( _ ). You do not have to use all 12 character s but the fir st cha ract er must al ways be a letter .

Note: If you forget your security code, you can disable the security feature by adding a jumper inside the instrument as described on the following page.

Chapter 4 Calibration Procedures

Calibration Security

To Unsecure the Instrum ent Without the Sec urity Code

To unsecure the instrument without the correct security code, follow the steps below. A front panel procedure to unsecure the instrument is given on page 51. See “Electrostatic Discharge (ESD) Precautions”

on page 162 before beginning this procedure.

Warning

• Exposed Mains

• Do Not Touch!

SHOCK HAZARD. Only service-trained personnel who are aware of the hazards involved should remove the instrument covers. The procedures in this section require that you connect the power cord to the instrument with the covers removed. To avoid electrical shock and personal injury, be careful not to touch the power-line connections.

1 Disconnect the power cord and all input connections. 2 Remove the instrument cover (see page 174). Turn the instrument over. 3 Apply power and turn on the instrument.

Be careful not to touch the power line connectio ns.

4 Apply a short between the two exposed metal pads marked

CAL UNLOCK as shown in the figure below.

Apply Short

5 While maintaining the short, enter any unsecure code.

The instrument is now unsecured.

6 Remove the short. 7 Turn off the instrument and remove the power cord. Reassemble the

instrument.

Now you can enter a new security code. Be sure to remember the new security code.

Chapter 4 Calibration Procedures

Calibration Message

The instrument allows you to store one message in calibration memory. For example, you can store such information as the date when the last calibration was performed, the date when the next calibration is due, the instrument’s serial number, or even the name and phone number of the person to contact for a new calibration.

• You can record a calibration message only from the remote

interface and only when the instrument is unsecured. You can read the message from either the front-panel or over the remote interface. You can read the calibration message whether the instrument is secured or unsecured.

• The calibration message may contain up to 40 characters. From

the front panel, you can view 13 chara cters of t he message at a t ime. Press to scroll through the text of the message. Press

again to increase the scrolling speed.

Calibration Count

You can query the instrument to determine how many calibrations have been performed. Note that your instrument was calibrated before it left the factory. When you receive your instrument, be sure to read the count to determine its initial value.

• The calibration count increments up to a maximum of 65,535 after

which it rolls over to “0”. Since the value increments by one for each calibration point, a complete calibration may increase the value by many counts.

• The calibration count is also incremented with calibrations of the

DAC channels on the multifunction module.

• Front-Panel Operation:

CAL COUNT

• Remote Interface Operation:

CALibration:COUNt?

Chapter 4 Calibration Procedures

Calibration Procedure

The following procedure is the recommended method to complete an instrument calibration.

1 Read “Test Considerations” (page 71). 2 Unsecure the instrument for calibration (page 51). 3 Perform the verification tests to characterize the instrument

(incoming data). 4 Perform the zero adjustment procedures. 5 Perform the gain adjustment procedures. Perform the verification

tests to verify the adjustments (outgoing data). 6 Secure the instrument against calibration. 7 Note the new security code and calibration count in the

instrument’s maintenance records.

CAUTION

Aborting a Calibration in Progress

Sometimes it may be necessary to abort a calibration after the procedure has already been initiated. You can abort a calibration at any time by turning off the power. When performing a calibration from the remote interface, you can abort a calibration by issuing a remote interface device clear message.

If you abort a calibration in progress when the instrument is attempting to write new calibration constants to EEPROM, you may lose all calibration constants for the function. Typ ic al ly , up on re-applying power, the instrument will report error 705 Cal:Aborted. You may also generate errors 740 through 746. If this occurs, you should not use the instrument until a complete re-adjustment has been performed.

Chapter 4 Calibration Procedures

Test Considerations

To ensure proper instrument operation, verify that you have selected the correct power line voltage prior to attempting any procedure in this chapter. See “If the Instrument Does Not Turn On”, on page 42.

Errors may be induced by ac signals present on the input leads during a self-test. Long test leads can also act as an antenna causing pick-up of ac signals.

For optimum performance, all procedures should comply with the following recommendations:

• Assure that the calibration ambient temperature is stable and

between 18 performed at 23

• Assure ambient relative humidity is less than 80%.

• Allow a 2-hour warm-up period with a copper short connected and

the multiplexer module installed before verification or adjustment. The connections are shown in the figure on page 66.

• Use shielded twisted pair Teflon

settling and noise er ro rs. Keep the inpu t ca bl es a s shor t a s p ossi ble.

• Connect the input cable shield to the source LO output.

Except where noted in the procedures, connect the calibrator LO source to earth ground.

Two-wire Ohms measurements are affected by the entire path length, including the plug-in card trace length and slot trace lengths. On the 34901A, Channel 10 is recommended as the median path length (on the 34902A, use Channel 8) for 2-wire Ohms verification and adjustments. Install the input multipl exer in sl ot 20 0.

Because the instrument is capable of making highly accurate measurements, you must take special care to ensure that the calibration standards and test procedures used do not introduce additional errors. Ideally, the standards used to verify and adjust the instrument should be an order of magnitude more accurate than each instrument range full scale error specification.

°C and 28 °C. Ideally the calibration should be

°C ±1 °C.

insulated cables to reduce

For the dc voltage, dc current, and resistance gain verification measurements, you should take care to ensure the calibrator’s “0" output is correct. If necessary, the measurements can be referenced to the calibrator’s ”0" outpu t using Mx + B scal ing (se e page 54). You will need to set the offset for each range of the measuring function being verified.

Chapter 4 Calibration Procedures

Performance Verification Tests

Use the Performance verification Tests to verify the measurement performance o f the instrument . The performance verification tests use the instrument’s specifi cation s listed in c hapt er 1, “Speci ficati ons,” starting on page 15.

You can perform four different levels of performance verification tests:

• Self-Test A series of internal verification tests that give a high

confidence that the instrument is operational.

• Quick Verification A combination of the internal self-tests and

selected verification tests.

• Performance Verification Tests An extensive set of tests that

are recommended as an acceptance test when you first receive the instrument or afte r performing adjustments.

• Optional Ver i f i cation Tests Tests not perfor med with every

calibration. Perform these tests to verify additional specifications or functions of the instrument.

Chapter 4 Calibration Procedures

Performance Verification Tests

Self-Test

A brief power-on self-test occurs automatically whenever you turn on the instrument. This limi ted test assur es that the instrum ent is capa ble of operation and also checks the plug-in cards for basic operation.

To perform a complete self-test hold down the key as you press the power switch to turn on the instrument; hold down the key

for more than 5 seconds until the instrument beeps (a complete description of these tests can be found in chapter 6). The instrument will automatically perform the complete self-test procedure when you release the key. The self-test will complete i n approximately 20 seconds.

• If the self-test is successful, “PASS” is displayed on the front panel.

• If the self-test fails, “FAIL” is displayed and the ERROR

annunciator turns on. If repair is required, see chapter 6, “Service,” for further details.

• If all tests pass, you have a high confidence (~90%) that the

instrument is operational.

Chapter 4 Calibration Procedures

Performance Verification Tests

Quick Performance Check

The quick performance check is a combination of internal self-test and an abbreviated performance test (specified by the letter Q in the performance verification tests). This test provides a simple method to achieve high confidence in the instrument’s ability to functionally operate and meet specifica tions. These tests represent the absolute minimum set of performance checks recommended following any service activity. Auditing the instrument’s performance for the quick check points (designated by a Q) verifies performance for “normal” accuracy drift mechanisms. This test does not check for abnormal

component failures.

To perform the quick performance check, do the following:

• Perform a complete self-test. A procedure is given on page 73.

• Perform only the performance verification tests indicated with the

letter Q .

If the instrument fails the quick performance check, adjustment or repair is required.

Performance Verification Tests

The performance verification tests are recommended as acceptance tests when you first receive the instrument. The acceptance test results should be compared against the 90 day test limits. You should use the 24-hour test limits only for verification within 24 hours after performing the adjustment procedure. After acceptance, you should repeat the performance verification tests at every calibration interval.

If the instrument fails performance verification, adjustment or repair is required.

Adjustment is recommend ed at every calib ration inte rval. I f adjustm ent is not made, you must guar d ban d, using no more than 80 % of the specifications listed in Chap ter 1, as the ver ifica tion lim its.

Chapter 4 Calibration Procedures

Internal DMM Verification Tests

These procedures use inputs connected to a 34901A 20-Channel Multiplexer (see page 66) installed in slot 200.

Zero Offset Verification

This procedure is used to check the zero offset performance of the internal DMM. Verification checks are only performed for those functions and ranges with unique offset calibration constants. Measurements are checked for each function and range as described in the procedure below.

Zero Offset Veri f ication Procedure

1 Make sure you have read “Test Considerations” on page 71. 2 This procedure will measure the shorts installed on Channels 209

and 219. Leave the Am ps input c o n nections ( C hanne l 221) open .

Continued on next page...

Chapter 4 Calibration Procedures

Internal DMM Verification Tests

Continued from previous page...

1 Select each function and range in the order shown in the table below.

Before executing each test, you must press to enable reading monitoring on the selected channel (or use the ROUTe:MON command from the remote interface). Compare measurement results to the appropriate test limits shown in the table (see page 74).

Input

Open Open Open

Input

Short Short Short Short Short

Short

2-Wire Ohms Short Short Short Short Short Short

[1] Select 61⁄2 digit resolution. [2] For 2-wire ohms, an additional 4

Q: Quick performance verification test points.

Channel 221

[1]

Function

Range

DC Current 10 mA

100 mA 1 A

Channel 209

[1]

Function

Range

DC Volts 100 mV

1 V 10 V 100 V 300 V

[2]

100

and

4-Wire Ohms

1 kΩ 10 kΩ 100 kΩ 1 MΩ 10 MΩ 100 MΩ

Ω

Ω of error must be added.

Quick

Check

Quick

Check

Error from Nominal

24 hour 90 day 1 year

± 1 µA ± 4 µA ± 60 µA

± 2

± 5 µA ± 100 µA

µA

± 2 µA ± 5 µA ± 100 µA

Error from Nominal

24 hour 90 day 1 year

µV

± 3.5

± 6 µV ± 40 µV ± 600 µV ± 6 mV

± 3.5 mΩ

6 mΩ

50 mΩ

± ±

500 mΩ 10 Ω

± ±

100 Ω 10 kΩ

± 4 µV ± 7 µV ± 50 µV ± 600 µV ± 9 mV

4 mΩ 10 mΩ

100 mΩ

± ±

1 Ω 10 Ω

± ±

100 Ω 10 kΩ

± 4 µV ± 7 µV ± 50 µV ± 600 µV ± 9 mV

± ± ± ± ± ± ±

Note: Zero offset calibration using a multifunction calibrator is NOT recommended. The c alibrator and cabling offset can be large and unstable causing poor offset calibration of the internal DMM.

4 mΩ 10 mΩ 100 mΩ 1 Ω 10 Ω 100 Ω 10 kΩ

Chapter 4 Calibration Procedures

Internal DMM Verification Tests

Gain Verification

This procedure is used to check the “full scale” reading accuracy of the internal DMM. Verification checks are performed only for those functions and ranges with unique gain calibra tion constants. Begin verification by selecting a measuring function and range.

Make sure you have read “Test Considerations” on page 71.

DC VOLTS, Resistance, and DC CURRENT Gain Verification Test

1 Make sure you have read “Test Considerations” on page 71. 2 Select each function and range in the order shown below.

Before executing each test, you must press to enable reading monitoring on the selected channel (or use the ROUTe:MON command from the remote interface).

3 Compare measurement results to the appropriate test limits shown

in the table. (Be certain to allow for appropriate source settling.)

Input

100 mV 1 V 10 V 100 V 300 V

Channel 210

[1]

Function

Range

DC Volts 100 mV

1 V 10 V 100 V 300 V

Quick

Check

Q Q

Error from Nominal

24 hour 90 day 1 year

± 6.5 µV ± 26 µV ± 190 µV ± 2.6 mV ± 12 mV

± 8 µV ± 37 µV ± 250 µV ± 4.1 mV ±

± 9 µV ± 47 µV ± 400 µV ± 5.1 mV ± 22.5 mV

19.5 mV

100 1 kΩ 10 kΩ

Ω

2-Wire Ohms

and

4-Wire Ohms

100 kΩ

Ω

1 M 10 M

Ω

[3]

Ω

100 M

Input

10 mA

Function

DC Current 10 mA 100 mA 1 A

[1] Select 61⁄2 digit resolution. [2] The 2-wire ohms resistance verification test is optional (see note on Page 82). For 2-wire ohms, an additional 4 Fluke 5700 in 2-wire compensated mode. This avoids response time issues with 2-wire compensation when 34970A’s current source contains a pulse. [3] Verify only, no adjustment required. Q: Quick performance verification test points.

[2]

Channel 221

[1]

Range

Ω of error must be added. Add a 1-second channel delay when using

Ω

100

Ω

1 k 10 k

Ω

100 kΩ 1 MΩ 10 MΩ 100 MΩ

100 mA 1 A

Quick

Check

± 6.5 mΩ ±

26 mΩ 250 mΩ

± ±

2.5 Ω

30 Ω

1.6 kΩ

± ±

310 kΩ

24 hour 90 day 1 year

± 1.5 µA ± 14 µA ± 560 µA

12 mΩ

90 mΩ 900 mΩ

± ±

9 Ω

90 Ω

2.1 kΩ

± ±

801 kΩ

14 mΩ

110 mΩ

1.1 Ω

± ±

11 Ω

110 Ω

4.1 kΩ

± ±

810 kΩ

Error from Nominal

± 5 µA ± 35 µA ± 900 µA

± 7 µA ± 55 µA ± 1.1 mA

Chapter 4 Calibration Procedures

Internal DMM Verification Tests

AC VOLTS Gain Verification Test

Configuration: AC Volts

LF 3 HZ:SLOW (in the Advanced menu)

1 Make sure you have read “Test Considerations” on page 71. 2 Select Channel 210, set the AC VOLTS function and the 3 Hz input

filter. With the slow filter selected, each measurement takes 7 seconds to complete. Before executing each test, you must press to

enable reading monitoring on the selected channel (or use the ROUTe:MON command from the remote interface).

3 Select each range in the order shown below. Compare measure ment

results to the appropriate test limits shown in the table. (Be certain to allow for appropriate source settling.)

Input

V rms Frequency

100 mV 100 mV 1 V 1 V 10 V 10 V 10 V 10 mV 100 V 100 V 300 V 300 V

[1] For this test, isolate the calibrator’s output from earth ground. [2] Some calibrators may have difficulty driving the internal DMM and cable load at this

V-Hz output. Use short, low capacitance cable to reduce calibration loading. Verification can be performed at >195 Vrms. New test limits can be computed from the accuracy specification shown in Chapter 1 for the actual test conditions used.

Q: Quick performance verification test points.

1 kHz 50 kHz 1 kHz 50 kHz 1 kHz 50 kHz 10 Hz

[1]

1 kHz 1 kHz 50 kHz 1 kHz

[2]

50 kHz

Range

100 mV 1 10 V

100 mV 100 V

300 V

Quick

Check

Error from Nominal

24 hour 90 day 1 year

± 70 µV ± 150 µV

± 700 µV ± 1.5 mV ± 7 mV ± 15 mV ± 7 mV ± 34 µV ± 70 mV ± 150 mV ± 270 mV ± 600 mV

± 90 µV

± 160 µV

± 900 µV ± 1.6 mV ± 9 mV ± 16 mV ± 9 mV ± 45 µV ± 90 mV ± 160 mV ± 390 mV ± 690 mV

Note: The 50 kHz ac voltage test points may fail performance verification if the internal shields have been removed and reinstalled. See “Gain Adjustment,” on page 82, for further information on how to recalibrate the ac voltage function.

± 100 µV ± 170 µV ± 1 mV ± 1.7 mV ± 10 mV ± 17 mV ± 10 mV ± 46 µV ± 100 mV ± 170 mV ± 420 mV ± 720 mV

Chapter 4 Calibration Procedures

Internal DMM Verification Tests

AC CURRENT Gain Verification Test

Configuration: AC Current

LF 3 HZ:SLOW (in the Advanced menu)

1 Make sure you have read “Test Considerations” on page 71. 2 Select Channel 221, set the AC CURRENT function and the 3 Hz

input filter. With the slow filter selected, each measurement takes 7 seconds to complete. Before executing each test, you must press

to enable reading monitoring on the selected channel (or use the

ROUTe:MON command from the remote interface).

3 Select each range in the order shown below. Compare measurement

results to the appropriate test limits shown in the table. (Be certain to allow for appropriate source settling.)

Input

Current Frequency

[1]

10 mA 100 mA 10 mA 1A

[1] Verify only, no adjustment.

[1]

1 kHz 1 kHz 1 kHz 1 kHz

Range

10 mA

100 mA

1 A

Quick

check

Error from Nominal

24 hour 90 day 1 year

± 14 µA ± 600 µA ± 1.41 mA ± 1.4 mA

Frequency Gain Verification Test

Configuration: Frequency

⁄

digits

1 Make sure you have read “Test Considerations” on page 71. 2

Select Channel 210, select the FREQUENCY function and set 6

⁄

digits.

3 Select each range in the order shown below. Compare measure ment

results to the appropriate test limits shown in the table. (Be certain to allow for appropriate source settling.)

Input

Voltage Frequency

[1]

10 mV 1 V

[1] Verify only, No adjustment. For this test, isolate the calibrator’s output from earth ground. Q: Quick performance verification test points.

100 Hz 100 kHz

Range

100 mV 1 V

Quick

Check

Error from Nominal

24 hour 90 day 1 year

± 0.06 Hz ± 6 Hz

± 0 .1 Hz ± 10 Hz

Chapter 4 Calibration Procedures

Optional AC Performance Verification Tests

These tests are not intended to be performed with every calibration. They are provided as an aid for verifying additional instrument specifications. There are no adjustments for these tests; they are provided for performance verification only.

Configuration: AC VOLTS

LF 3 HZ:SLOW (in the Advanced menu)

1 Make sure you have read “Test Considerations” on page 71. 2 Select Channel 210, select the AC Volts function and the 3 HZ filter.

Before executing each test, you must press to enable reading monitoring on the selected channel (or use the ROUTe:MON command from the remote interface).

3 Select each range in the order shown below. Compare measure ment

results to the appropriate test limits shown in the table. (Be certain to allow for appropriate source settling.)

Input

Voltage Frequency

1 V 1 V 1 V 1 V

10 V 1 V 100 mV

20 Hz 20 kHz 100 kHz 300 kHz

1 kHz 1 kHz 1 kHz

Range

1 V 1 V 1 V 1 V

10 V 10 V 10 V

Error from Nominal

24 hour 90 day 1 year

± 700 µV ± 700 µV ± 6.3 mV ± 45 mV

± 7 mV ± 3.4 mV ± 13 mV

± 900 µV ± 900 µV ± 6.8 mV ± 45 mV

± 9 mV ± 4.5 mV ± 14 mV

± 1 mV ± 1 mV ± 6.8 mV ± 45 mV

± 10 mV ± 4.6 mV ± 14 mV

Chapter 4 Calibration Procedures

Internal DMM Adjustments

You will need a 34901A 20-Channel Multiplexer to perform the following procedures (see page 66). Install the Multiplexer in slot 200.

Zero Adjustment

Each time you perform a zero adjustment, the Internal DMM stores a new set of offset correction constants for every measurement function and range. The Internal DMM will sequence through all required functions and ranges automatically and st ore new zero offset cal ibrat ion constants. All offset corrections are determined automatically. You may

not correct a single range or function without re-entering offset correction constants automatically. This feature is intended to save calibration time and improve zero calibration consistency.

ALL zero

Note: Never turn off the Internal DMM during Zero Adjustment. This may cause ALL calibration memory to be lost.

Zero Adjustment Procedure

The zero adjustment procedure takes about 5 minutes to complete. Be sure to allow the instrument to warm up for 2 hours before performing the adjustments.

Follow the steps outlined below. Review “Test Considerations” on page 71 before beginning this test. Also see page 53, for an example of how to initiate a zero calibration.

1 This procedure will use the copper shorts installed on Channels 209

and 219. Leave the Amps input connections (Channel 221) open.

2 Select Channel 209. Select the DC VOLTS function. 3

Press to enter the calibration menu. Press again to begin the adjustment procedure.

4 Use the knob and arrow keys to set the number in the display

to 0.000000 and press .

5 Perform the Zero Offset Verification tests (see pag e 75) to check zero

calibration results.

Chapter 4 Calibration Procedures

Internal DMM Adjustments

Gain Adjustment

The Intern al DMM stores a single new gain correction constant each time this procedure is followed. The gain constant is computed from the calibration value entered for the calibration command and from measurements made automatically during the adjustment procedure.

Most measuring functions and ranges have gain adjustment procedures. Only the 100 M procedures. The gain calibration value may be entered through the front panel menu or over the remote interface. See page 53, for an example of how to enter calibration values.

Adjustments for each function should be performed ONLY in the order shown in the performance verification table. See “Performance Verification Tests” earlier in this chapter for the tables used for gain adjustments.

Gain Adjustment Considerations

• The zero adjustment procedure must have been recently performed

prior to beginning any gain adjustment procedures.

Ω range does not have gain calibration

• The optional –10 Vdc adjustment should be performed only after

servicing the Internal DMM’s a-to-d converter or after replacing network A4

• When performing a 4-wire ohms gain adjustment, a new gain

correction constant is also stored for the corresponding 2-wire ohms measurement range. If desired, the 2-wire gain can be adjusted separately after the 4-wire ohms gain calibration is completed.

• During the ac voltage gain adjustments, some of the dc voltage

gain constants are used. Perform the dc voltage gain calibration before the ac voltage gain calibration.

Note: Never turn off the instrument during a Gain Adjustment. This may cause calibration memory for the present function to be lost.

U101 or calibration RAM A4U505.

Chapter 4 Calibration Procedures

Internal DMM Adjustments

Valid Gain Adjustment Input Values

Gain adjustment can be accomplished using the following input values.

Function Range

DC VOLTS

OHMS, OHMS 4W DC CURRENT AC VOLTS [1]

AC CURRENT Frequency

[1] Valid frequencies are as follows: 1 kHz ± 10% for the 1 kHz calibration,

100 mV to 100 V 300 V

Ω to 10 MΩ

100 10 mA to 1 A 10 mV to 100 V

300 V 1 A Any

45 kHz – 100 kHz for the 50 kHz calibration, and 10 Hz

Valid Calibration Input

Values

0.9 to 1.1 x Full Scale 250 V to 303 V

0.9 to 1.1 x Full Scale

0.9 to 1.1 x Full Scale 95 V to 303 V

9 mA to 11 mA Any Input > 100 mV rms,

1 kHz – 100 kHz

± 10% for the 10 Hz calibration.

Chapter 4 Calibration Procedures

Internal DMM Adjustments

Gain Adjustment Procedure

Adjustment for each function should be performed only in the order shown in the performance verification table. The performance verification tables used for gain adjustments start on page 77.

Review the “Test Considerations” (page 71) and “Gain Adjustment Considerations” (page 82) sections before beginning this test.

Configuration: DC functions — 6

⁄

digits

AC functions — LF 3 HZ:SLOW (in the Advanced menu)

1 Select Channel 210. Configure the channel to each function and

range shown in the gain verification tables (pages 75 – 79).

2 Apply the input signal shown in the “Input” column of the

appropriate verification table.

Note: Always complete tests in the same order as shown in the appropriate verification table.

Press to enter the calibration menu. Press again to begin the adjustment procedure.

Use the knob, and to set the number in the display to the actual input value and press .

5 Perform the appropriate Gain Verification Test to check the

calibration results.

6 Repeat steps 1 through 6 for each gain verification test point shown

in the tables.

Note: Each range in the gain adjustment procedure takes less than 20 seconds to complete.

Chapter 4 Calibration Procedures

–10 Vdc Adjustment Procedure (Optional)

The –10 Vdc calibration electronically enhances the Internal DMM’s a-to-d converter linearity characteristic. This adjustment should

ONLY be performed after servicing the A-to-D converter or replacement of the calibration RAM.

You will need a 34901A 20-Channel Multiplexer to perform the following procedures (see page 66). Install the Multiplexer in slot 200.

1 If a zero calibration has not been performed recently, perform one

before beginning this procedure (see page 81).

2 Select Channel 210. Configure the channel as follows:

DC VOLTS 10 V range

⁄

digits

INTEG 100 PLC (in the Advanced menu) INPUT R > 10 G (in the Advanced menu)

Before executing each test, you must press to enable reading monitoring on the selected channel (or use the ROUTe:MON command from the remote interface).

3 Measure and note the voltage offset present at the end of the

measurement cable by shorting the ends of the Channel 210 measurement cable. Be sure to use a copper wire and allow enough time for the residual thermal offset to stabilize (usually about 1 minute).

4 Connect the input cable to the calibrator output and set the calibrator

to output +10V. Allow enough settling time for any thermal offset voltages to stabilize (usually about 1 minute).

Perform a +10V dc gain calibration. Press to enter the calibration menu. Press again to begin the adjustment procedure.

Use the knob, and to set the number in the display to the sum of the calibrator output and the measured offset (from step 3)

and press . For example, if the calibrator output is 10.001 volts and the measured offset is 10 adjustment finishes, verify that new readings fall within the calibrator output plus the offset.

µV, enter +10.001010 volts. When the

± 20 µV of

Continued on next page...

Chapter 4 Calibration Procedures

–10 Vdc Adjustment Procedure (Optional)

Continued from previous page...

1 Reverse the cable connections to the calibrator to create a -10 Vdc

voltage standard. You must physically reve rse the cables. DO NOT switch the output polarity of the calibrator.

Perform a –10V DC gain calibration. Press to enter the calibration menu. Press again to begin the adjustment

procedure. Be sure to allow time for thermal offsets to stabilize (usually about 1 minute).

Use the knob and to set the number in the display to the difference of the calibrator output and the measured offset (from step 3)

and press . Using the previous example values, enter 10 minus 10.001 volts or –10.000990 volts.

4 When the adjustment finishes, verify that new readings fall

within

± 30 µV of the calibrator output minus the offset.

µV

Chapter 4 Calibration Procedures

Plug-in Module Test Considerations

For optimum performance, all test procedures should comply with the following recommendations:

• Assure that the calibration ambient temperature is stable and

between 18 performed at 23

• Assure ambient relative humidity is less than 80%.

• Install the plug-in module and allow a 45 minute warm-up period

before verification or adjustment.

• Use shielded twisted pair Teflon

and noise errors. Keep the input cables as sh ort as possible.

• Remove all user wiring and connections from the plug-in modules

before verification or adjustment.

• Use 4-wire Ohms measurement techniques for checking relay

contact resistance. Check directly at the terminals where possible.

°C and 28 °C. Ideally the calibration should be

°C ± 1 °C.

insulated cables to reduce settling

Module Reference

Chapter 4 Calibration Procedures

Relay Verification

There are two methods you can use to verify relays:

• Read the relay cycle count.

• Measure the relay contact resistance.

Relay Cycle Co unt

• In addition to the channel relays, you can also query the count on

backplane rela y s a nd ban k re l ays. Not e that you cannot cont rol the state of these relays from the front panel b ut you can q uery t he count.

• You can also query the stat e of th e three r elays on the int ernal DMM.

These relays are numbered “1”, “2”, and “3” (which correspond to relays K102, K103, and K104 respectively). These relays open or close when a function or range is changed on a module.

DMM.

• The 34908A mult ipl ex er c on t ain s 4 0 ch anne l s whi c h a r e swi tch ed

HI only) using only 20 relays. Each relay is used to switch HI on two

( different channels (and only one channel can be closed at a time). The channels are arranged such that channels 01 and 21 use different contacts on the same relay. The remaining channels are also paired in the same manner (Channels 02 and 22, Channels 03 and 23, etc.). Therefore, when you query the relay count on a channel, the number reflects the number of times that the relay was closed. For example, the relay count w i ll a lw ay s b e t he sa me on Ch ann el s 0 1 and 21 .

• You can reset the count (allowed only from remote) but the

instrument must be unsecured (see “To Unsecure for Calibration” on page 51 to unsecure the instrument).

• For more information on relay life and load considerations, refer to

“Relay Life and Preventative Maintenance” in Chapter 8 of the 34970A User’s Guide.

• A procedure to read the relay cycle count i s given on page 55 .

Chapter 4 Calibration Procedures

Relay Verification

(Optional)

34901A Relay Contact Resistance Verification

This optional procedure uses an external DMM to make 4-wire ohms measurements across the relay contacts on the 34901A. The measured resistance is the series resistance of the two relay contacts (both contacts are in the same relay).

Note: Be sure to read “Plug-in Module Test Considerations” on page 87.

Tests 1 - 5: See the diagram on page 90 for the required connections for each test

(be sure to probe the components at the indicated location). For these measurements, the 34901A is not installed in the 34970A. Record the 4-wire ohms measurements from the external DMM in the table below.

Note: The connections to the external DMM are different for each of Tests 1, 2, 4, and 5. Be sure to verify the connections shown in the table below for each of the four tests.

External DMM Ohmmeter Connections

Test

1 L401 J101, C14 L401 J101, C14 __________ Ohms

HI LO

Sense

Measured

Value

Module Reference

2 L402 J101, C15 L402 J101, C15 __________ Ohms 3 Add (Test 1 + Test 2) __________ Ohms 4F501 5F502

Ch 21 I Ch 22 I

F501 F502

Ch 21 I Ch 22 I

__________ Ohms __________ Ohms

Chapter 4 Calibration Procedures

Relay Verification

Note: Connect bare copper wires (approximately 3 cm in length) to the I terminals of Channels 21 and 22 as shown below. These wires will be used to make shorts across the channels in Tests 6 through 39.

Note: Be sure to probe the components at the indicated locations on the module.

Probe here for L402 measurement.

Probe here for F501 measurement. Probe here for F502 measurement.

Connections for 34901A Verification Tests 1 through 5

Chapter 4 Calibration Procedures

Relay Verification

Tests 6 - 8: Make the connections to the 34901A as shown in the diagram below.

Be sure to route your wiring for proper strain relief and install the module cover. Install the 34901A in slot 200 of the 34970A. Open all channels on the module by performing a Factory Reset (press and select “Recall St at e”; press again and select “Factory R eset” ). Configure Channel 20 as foll ows: DC volt s, 10 volt r ange, and 5

⁄

digits.

Module Reference

Channel 20 should be left open.

Connections for 34901A Verification Tests 6 through 39

Enable reading monitoring by pressing on the selected channel (or use the ROUTe:MON command). Record the 4-wire ohms measurements from the external DMM in the following table.

External DMM Ohmmeter Connections

Test#Channel

Configured

6 Ch 20 P2 P2 P1 P1 __________ Ohms 7 Ch 20 P2 P2 P3 P3 __________ Ohms — — 8 Subtract (Test 7 – Test 6) __________ Ohms

HI LO

SenseLOSense

Measured Value

Test

Limit

2.00Ω

Measured

Relay

K421

K422

Chapter 4 Calibration Procedures

Relay Verification

Tests 9 - 10: Open all channels on the module by performing a Factory Reset.

Configure Channel 10 (module in slot 200) as follows: 4-wire ohms, 1 k

Ω range, and 51⁄

digits.

Enable reading monitoring by pressing on the selected channel (or use the ROUTe:MON command). Record the 4-wire ohms measurements from the external DMM in the following table.

External DMM Ohmmeter Connections

Test#Channel

Configured

9 Ch 10 P2 P2 P3 P3 __________ Ohms — —

10 Subtract (Test 9 – Test 3) __________ Ohms

HI LO

SenseLOSense

Measured Value

Test

Limit

2.00Ω

Tests 11- 33: Open all channels on the module by performing a Factory Reset.

For each test, close only the channel shown in the “Channel Closed” column below (module in slot 200). Turn the Monitor Mode “off” and select “Banks Joined” from the Advanced menu. Record the 4-wire ohms measurements from the external DMM in the following table.

External DMM Ohmmeter Connections

Test#Channel

Closed*

11 Ch 1 P2 P2 P1 P1 __________ Ohms 12 Ch 2 P2 P2 P1 P1 __________ Ohms 13 Ch 3 P2 P2 P1 P1 __________ Ohms 14 Ch 4 P2 P2 P1 P1 __________ Ohms

HI LO

SenseLOSense

Measured Value

Test

Limit

2.00Ω

Relay

Measured

K423

Relay

Measured

K401 K402 K403

K404 15 Ch 5 P2 P2 P1 P1 __________ Ohms 16 Ch 6 P2 P2 P1 P1 __________ Ohms 17 Ch 7 P2 P2 P1 P1 __________ Ohms

* Only the channel currently under test should be closed at one time. All other channels s hould be open.

2.00Ω

K405

K406

K407

Continued on next page...

Chapter 4 Calibration Procedures

Relay Verification

... Continued from previous page

External DMM Ohmmeter Connections

Module Reference

Test#Channel

Closed*

18 Ch 8 P2 P2 P1 P1 __________ Ohms 19 Ch 9 P2 P2 P1 P1 __________ Ohms 20 Ch 10 P2 P2 P1 P1 __________ Ohms 21 Ch 11 P2 P2 P1 P1 __________ Ohms 22 Ch 12 P2 P2 P1 P1 __________ Ohms 23 Ch 13 P2 P2 P1 P1 __________ Ohms 24 Ch 14 P2 P2 P1 P1 __________ Ohms 25 Ch 15 P2 P2 P1 P1 __________ Ohms 26 Ch 16 P2 P2 P1 P1 __________ Ohms 27 Ch 17 P2 P2 P1 P1 __________ Ohms 28 Ch 18 P2 P2 P1 P1 __________ Ohms 29 Ch 19 P2 P2 P1 P1 __________ Ohms 30 Ch 21 P4 P4 P5 P5 __________ Ohms — —

HI LO

SenseLOSense

Measured Value

Test

Limit

2.00Ω

Measured

Relay

K408 K409 K410 K411 K412 K413 K414 K415 K416 K417 K418 K419

31 Subtract (Test 30 – Test 4) __________ Ohms 32 Ch 22 P4 P4 P5 P5 __________ Ohms — — 33 Subtract (Test 32 – Test 5) __________ Ohms

* Only the channel currently under test should be closed at one time. All other channels s hould be open.

2.00Ω

K522

Chapter 4 Calibration Procedures

Relay Verification

Tests 34 - 36: Close only channels Channels 20 and 22. Remove the 34901A from the

34970A and do not reinstall it for these tests. On connector J101, remove the jumper between pins C14 and C15

(the top jumper shown in the diagram on page 91). On the remaining jumper connected to J101 (the bottom jumper shown in the diagram), move the end of the jumper from pin C12 to pin C16; the jumper should now short pins C13 and C16 together.

Cut, but do not remove, the copper shorts on Channels 21 and 22 (the wires will be used for the 4-wire ohms measurements below). Add a copper short between the L and H terminals on Channel 20. Record the measured value as Test 34 in the table below.

Using the external DMM, make a 4-wire ohms measurement between the L and I terminals on Channel 21. Record the measured value as Test 35 in the table below.

External DMM Ohmmeter Connections

Test#Channel

Closed

34 Ch 20* P3 P3 P2 P2 _________ _ Ohm s 35 Ch 22* 36 Subtract (Test 35 – Test 4) __________ Ohms

* The latching relay s remai n cl os ed wh en the mod ul e is remo ve d fro m th e 34 970A.

HI LO

Ch 21 I

Ch 21 L

SenseLOSense

Ch 21 I

Ch 21 L __________ Ohm s — —

Measured Value

Test

Limit

2.00Ω

Relay

Measured

K420

K523

Chapter 4 Calibration Procedures

Relay Verification

Test 37: Install the 34901A in slot 200 of the 34970A. Select and configure

Channel 21 as follows: DC current, 1 amp range, and 5

⁄

digits.

Enable reading monitoring by pressing on the selected channel (or use the ROUTe:MON command). Record the 4-w ire ohms measurement from the external DMM in the following table.

External DMM Ohmmeter Connections

Test#Channel

Configured

37 Ch 21 P4 P4 P5 P5 __________ Ohms

HI LO

SenseLOSense

Measured Value

Test

Limit

2.00Ω

Measured

Tests 38 - 39: Open all channels on the module by performing a Factory Reset.

Close Channel 21 (module in slot 200). Remove the 34901A from the 34970A and do not reinstall it for the remaining tests. Using the external DMM, make a 4-wire ohms measurement between the L and I terminals on Chann el 22. Reco rd the mea sured value as Test 38 in the following table.

External DMM Ohmmeter Connections

Module Reference

Relay

K521

Test#Channel

Closed

38 Ch 21 39 Subtract (Test 38 – Test 5) __________ Ohms

HI LO

Ch 22 I

Ch 22 L

SenseLOSense

Ch 22 I

Ch 22 L __________ Ohm s — —

Measured Value

Test

Limit

2.00Ω

Relay

Measured

K524

Chapter 4 Calibration Procedures

Relay Verification

(Optional)

34902A Relay Contact Resistance Verification

This optional procedure uses an external DMM to make 4-wire ohms measurements across the relay contacts on the 34902A. The measured resistance is the series resistance of the two relay contacts (both contacts are in the same relay).

Note: Be sure to read “Plug-in Module Test Considerations” on page 87.

Tests 1 - 4: See the diagram on page 97 for the required connections for each test

(be sure to probe the components at the indicated location). For these measurements, the 34902A is not installed in the 34970A. Record the 4-wire ohms measurements from the external DMM in t he t able bel ow.

Note: The connections to the external DMM are different for each of Tests 1, 2, and 3. Be sure to verify the connections shown in the table below for each of the three tests.

External DMM Ohmmeter Connections

Test

1 L300 J101, C12 L300 J101, C12 __________ Ohms

HI LO

Sense

Measured

Value

2 L301 J101, C14 L301 J101, C14 __________ Ohms 3 L302 J101, C15 L302 J101, C15 __________ Ohms 4 Add (Test 2 + Test 3) __________ Ohms

Probe here for L302 and L301 measurements.

Chapter 4 Calibration Procedures

Relay Verification

Module Reference

Connections for 34902A Verification Tests 1 through 4

Chapter 4 Calibration Procedures

Relay Verification

Tests 5 - 8: Make the connections to the 34902A as shown in the diagram below.

Be sure to route your wiring for proper strain relief and install the module cover. Install the 34902A in slot 200 of the 34970A. Open all channels on the module by performing a Factory Reset (press and select “Recall St at e”; press again and select “Factory R eset” ). Configure Channel 16 as foll ows: DC volt s, 10 volt r ange, and 5

⁄

digits.

Connections for 34902A Verification Tests 5 through 27

Enable reading monitoring by pressing on the selected channel (or use the ROUTe:MON command). Record the 4-w ire ohms measurements from the external DMM in the following table.

External DMM Ohmmeter Connections

Test#Channel

Configured

5 Ch 16 P3 P3 P1 P1 __________ Ohms — — 6 Subtract (Test 5 – Test 1) __________ Ohms 7 Ch 16 P3 P3 P2 P2 __________ Ohms — — 8 Subtract (Test 6 – Test 5) __________ Ohms

HI LO

SenseLOSense

Measured Value

Test

Limit

2.00Ω

Measured

Relay

K326

K327

HP 34970a schematic

Specifications and Main Features

Frequently Asked Questions

User Manual