Fluke 8508A Reference Multimeter

8508A

Reference Multimeter

Users Manual

Pn 1673798

Limited Warranty And Limitation Of Liability

This Warranty Is Buyer'S Sole And Exclusive Remedy And Is In Lieu Of All Other

For Any Special, Indirect, Incidental, Or Consequential Damages Or Losses,

Including Loss Of Data, Arising From Any Cause Or Theory.

U.S.A.

11/99

To register your product online, visit register.fluke.com

i Table of Contents Chapter Title Page 1 Introduction and Safety Information .................................................. 1-1 Introduction ........................................................................................................ 1-3 How to Contact Fluke ........................................................................................ 1-3 Unpacking and Inspection.................................................................................. 1-4 Standard Accessories ..................................................................................... 1-4 Optional Accessories ..................................................................................... 1-5 Storing and Shipping the Multimeter ................................................................. 1-6 Line Voltage ...................................................................................................... 1-6 Power Voltage Selector and Fuses ................................................................ 1-6 Changing Supply Voltage or Replacing Line Fuse ....................................... 1-6 Calibration Enable Switch ................................................................................. 1-7 System Use .................................................................................................... 1-7 Safety Considerations and Symbols ................................................................... 1-7 General Safety Summary ............................................................................... 1-7 Safety Information ............................................................................................. 1-8 Symbols ............................................................................................................. 1-10 Protection Class I ........................................................................................... 1-11 Protective Earth/Ground ............................................................................ 1-11 Do Not Operate Without Covers ............................................................... 1-11 Safe Operating Conditions ........................................................................ 1-11 Fuse Requirements .................................................................................... 1-12 Rear Panel Detail ....................................................................................... 1-12 The Power Cable and Power Supply Disconnection ................................. 1-12 Terminal Connections ............................................................................... 1-13 Measurement Category I ............................................................................... 1-13 Maintenance and Repair ................................................................................ 1-13 Moving and Cleaning .................................................................................... 1-13 2 Getting Acquainted with the Basics .................................................. 2-1 Introduction ........................................................................................................ 2-3 Input Terminals .................................................................................................. 2-3 The Front Panel Displays ................................................................................... 2-4 Front Panel Keys ................................................................................................ 2-4 Soft-Keys and Manual Conventions .............................................................. 2-4 Numeric Keyboard ........................................................................................ 2-5

8508A

ii

Exiting a Menu .............................................................................................. 2-5 Major Function Keys ..................................................................................... 2-5 Direct Action Keys ........................................................................................ 2-6 Mode Keys..................................................................................................... 2-6 Rear Panel .......................................................................................................... 2-7 Labels ............................................................................................................ 2-7 Fuses .............................................................................................................. 2-7 Voltage Selector ............................................................................................ 2-7 Power Input and Power Switch ..................................................................... 2-7 Calibration Switch ......................................................................................... 2-7 Rear Panel Connectors and Pin Designations .................................................... 2-8 Rear Inputs..................................................................................................... 2-8 External Trigger Input ................................................................................... 2-8 IEEE 488 Input/Output .................................................................................. 2-8 Power-On Configuration .................................................................................... 2-8 The 8508A-LEAD Measurement Lead Kit ........................................................ 2-9 3 Making Measurements ........................................................................ 3-1 Introduction ........................................................................................................ 3-3 Making Connections to the Multimeter -- General Guidelines .......................... 3-4 Using the Measurement Functions ..................................................................... 3-5 DC Voltage .................................................................................................... 3-5 Measuring DC Voltage .................................................................................. 3-7 Making Input Connections ........................................................................ 3-7 AC Voltage .................................................................................................... 3-8 Measuring AC Voltage .................................................................................. 3-11 Induced Interference .................................................................................. 3-11 Common Mode Rejection ......................................................................... 3-11 Lead Considerations .................................................................................. 3-11 Resistance ...................................................................................................... 3-11 High Voltage Ohms ....................................................................................... 3-13 True Ohms ..................................................................................................... 3-15 Measuring Resistance .................................................................................... 3-17 2-Wire Measurements ............................................................................... 3-17 4-wire Measurements ................................................................................ 3-17 4-wire High Resistance Measurements ..................................................... 3-18 4-wire Resistance Zero .............................................................................. 3-18 Ω Guard ..................................................................................................... 3-19 DC Current .................................................................................................... 3-21 Measuring DC Current .................................................................................. 3-22 AC Current .................................................................................................... 3-23 Measuring AC Current .................................................................................. 3-24 Temperature ................................................................................................... 3-25 Measuring Temperature ................................................................................. 3-28 Multimeter Inputs .............................................................................................. 3-29 Input ............................................................................................................... 3-29 Using the INPUT Key ................................................................................... 3-29 SCAN OPERATIONS ................................................................................... 3-30 Tru Ohms Ratio ......................................................................................... 3-31 Monitoring Modes ............................................................................................. 3-32 Monitor Key .................................................................................................. 3-32 Displaying Signal Frequency......................................................................... 3-32 Displaying Standard Deviation ...................................................................... 3-32 Devn Menu ................................................................................................ 3-32

Contents (continued)

iii

Displaying Maximum, Minimum, and Peak-to-Peak Readings .................... 3-33 MAX Menu ............................................................................................... 3-33 Limit-Checking ......................................................................................... 3-33 Monitor Menu Tree ....................................................................................... 3-34 Utility ................................................................................................................. 3-34 Using the Selftest Functions .............................................................................. 3-37 Test Menu Tree .............................................................................................. 3-38 Test Key ........................................................................................................ 3-39 Using the Math Functions .................................................................................. 3-40 Math Functions and Menu Tree..................................................................... 3-40 Math Configuration ....................................................................................... 3-41 Clear Functions .................................................................................................. 3-42 4 Remote Operations Using the IEEE 488 Interface ............................ 4-1 Introduction ........................................................................................................ 4-3 Interface Capability: IEEE Standards 488.1 and 488.2 ..................................... 4-3 The Multimeter in IEEE 488.2 Terminology ................................................ 4-3 Programming Options ................................................................................... 4-3 Capability Codes ........................................................................................... 4-3 Interconnections ................................................................................................. 4-4 Using the 8508A Reference Multimeter in a System ........................................ 4-5 Setting the Multimeter Address ..................................................................... 4-5 Remote Operation General Considerations ................................................... 4-5 Syntax Diagrams in this Manual ................................................................... 4-5 The 8508A Status Reporting Structure .......................................................... 4-8 Types of Status Information Available .......................................................... 4-9 Syntax Diagrams of Major 8508A Functions .................................................... 4-10 DC Voltage .................................................................................................... 4-10 AC Voltage .................................................................................................... 4-11 Resistance: Normal OHMS ........................................................................... 4-13 Resistance: High Voltage OHMS .................................................................. 4-14 Resistance: True OHMS ................................................................................ 4-15 DC Current .................................................................................................... 4-16 AC Current .................................................................................................... 4-17 Using Platinum Resistance Thermometers to obtain Temperature. .............. 4-18 Determine the PRT identity. .......................................................................... 4-18 Entering or Editing the Characteristics of a PRT to Non-volatile Store ....... 4-19 Recalling the Characteristics of a Known PRT ............................................. 4-20 Deleting a Known PRT from the Non-volatile Store .................................... 4-20 Input ............................................................................................................... 4-21 Guard ............................................................................................................. 4-21 Measurement Gate Width .............................................................................. 4-22 Maximum, Minimum and Peak-Peak ............................................................ 4-22 Limits ............................................................................................................. 4-24 Recall Limits ................................................................................................. 4-24 Enable Limits ................................................................................................. 4-24 Standard Deviation ........................................................................................ 4-25 Syntax Diagrams of Math Functions ................................................................. 4-25 Averaging ...................................................................................................... 4-25 Multiplication ................................................................................................ 4-27 Subtraction ..................................................................................................... 4-28 Division ......................................................................................................... 4-29 Decibel Calculations ...................................................................................... 4-30 Syntax Diagram of Test ..................................................................................... 4-31

8508A

iv

Selftest ........................................................................................................... 4-31 Device Errors and Syntax Diagrams .................................................................. 4-31 Error Detection .............................................................................................. 4-31 Recall Device Errors ...................................................................................... 4-32 Triggering and Reading Operations ................................................................... 4-33 Trigger Source Selector ................................................................................. 4-33 Execute Trigger ............................................................................................. 4-34 Execute Trigger and Take a Reading ............................................................ 4-34 Settling Delay ................................................................................................ 4-34 Input Zero ...................................................................................................... 4-36 Wait ............................................................................................................... 4-36 Reading Recall ............................................................................................... 4-36 Access to the Internal Buffer Memory .......................................................... 4-37 Internal Operations Commands ......................................................................... 4-39 Reset .............................................................................................................. 4-39 Complete Operations ..................................................................................... 4-40 Status Reporting ................................................................................................. 4-40 Instrument I/D and Setup ................................................................................... 4-44 Calibration Commands and Messages ............................................................... 4-46 Calibration Sequences ................................................................................... 4-46 Protected User Data ....................................................................................... 4-48 Special Calibrations ....................................................................................... 4-49 5 Specifications ...................................................................................... 5-1 Specifications ..................................................................................................... 5-3 General Specifications ................................................................................... 5-3 Maximum Voltage and Current Inputs .......................................................... 5-4 DC and AC Voltage .................................................................................. 5-4 DC and AC Current ................................................................................... 5-4 Resistance and Temperature ..................................................................... 5-4 Electrical Measurement Specifications .............................................................. 5-5 DC Current .................................................................................................... 5-6 AC Voltage .................................................................................................... 5-7 AC Current .................................................................................................... 5-9 Resistance ...................................................................................................... 5-11 Temperature ................................................................................................... 5-13 Read Rate and Additional Uncertainty .......................................................... 5-14 Applying the Specifications ............................................................................... 5-15 Introduction ................................................................................................... 5-15 Absolute and Relative Specifications ............................................................ 5-15 Applying User’s Calibration Uncertainties ................................................... 5-16 Operating and Calibration Temperature Ranges ........................................... 5-16 Applying Temperature Coefficient Specifications ........................................ 5-16 Ratio Measurements ...................................................................................... 5-17 Additional Errors ........................................................................................... 5-17 6 Adjustment and Verification ............................................................... 6-1 Introduction ........................................................................................................ 6-3 Adjustment Overview ........................................................................................ 6-3 Adjustment Interval and Performance ............................................................... 6-3 Adjustment Points .............................................................................................. 6-3 Non-Nominal Values ..................................................................................... 6-4 Enabling Access to Calibration Adjustment Mode ............................................ 6-4 Calibration Menus .............................................................................................. 6-4

Contents (continued)

v

Accessing the Calibration Menus and Calibration Mode .............................. 6-4 Calibration Menu ........................................................................................... 6-5 SET VALUE Menu ....................................................................................... 6-5 SPOT CAL Menu .......................................................................................... 6-6 SPOT (1 to 6) RMS Menus ........................................................................... 6-6 SPOT FREQUENCY (1 to 6) Menu ............................................................. 6-7 Special Calibration ........................................................................................ 6-7 SPCL Menu ................................................................................................... 6-7 SER # Menu .................................................................................................. 6-8 Hvlin Menu .................................................................................................... 6-8 Non-volatile input offset compensation ............................................................. 6-9 Routine Adjustment ........................................................................................... 6-9 Equipment Required for Adjustment ............................................................. 6-10 Preparing for Adjustment .............................................................................. 6-11 Interconnections ............................................................................................ 6-12 ADC Adjustment ........................................................................................... 6-14 DC Voltage Adjustment ................................................................................ 6-14 AC Voltage Adjustment ................................................................................ 6-17 Resistance Adjustment .................................................................................. 6-19 AC Current Adjustment ................................................................................. 6-30 Frequency Adjustment ................................................................................... 6-32 Cal Due Date Entry ....................................................................................... 6-32 Non-Volatile Input Offset Adjustment .......................................................... 6-33 ACV Spot Frequency Adjustment ..................................................................... 6-34 Performance Verification ................................................................................... 6-35 Equipment Requirements .............................................................................. 6-36 Interconnections ............................................................................................ 6-36 Applicable Verification Tolerance and Conditions ....................................... 6-36 Preparation ..................................................................................................... 6-37 DC Voltage Checks ....................................................................................... 6-37 AC Voltage Checks ....................................................................................... 6-40 Resistance Checks ......................................................................................... 6-42 Normal Ω Checks .......................................................................................... 6-44 Normal LoI Ω checks .................................................................................... 6-44 Tru Ω checks ................................................................................................. 6-44 Tru Ω LoI checks ........................................................................................... 6-44 HiV Ω checks ................................................................................................ 6-44 DC Current Checks ........................................................................................ 6-46 AC Current Checks ........................................................................................ 6-48 Frequency Checks ......................................................................................... 6-50 Appendices A Error Codes and Message ............................................................................ A-1 B Rack Mount Kit ........................................................................................... B-1 C Rack Mount Slide Kit .................................................................................. C-1

8508A

vi

vii List of Tables Table Title Page 1-1. Standard Accessories ............................................................................................. 1-4 1-2. Additional Accessories for the Multimeter ............................................................ 1-5 1-3. Power Input Fuse 1 ................................................................................................. 1-12 1-4. Current Function Rear Input Fuse 2 ....................................................................... 1-12 3-1. Identifying and Avoiding Errors ............................................................................ 3-4 3-1. Additional Accessories for the Multimeter ............................................................ 3-19 4-1. IEEE Interface Capability ...................................................................................... 4-4 4-2. Delay Defaults for DCV, DCI, ACV, and ACI ...................................................... 4-35 4-3. Delay Defaults for Ohms, Tru Ohms, and Hi Ohms .............................................. 4-35 6-1. Required Equipment for Calibration and Performance Verification ...................... 6-10 6-2. Calibration Sequence ............................................................................................. 6-12 6-3. DC Voltage Calibration Points and Sequence ........................................................ 6-15 6-4. AC Voltage Calibration Points and Sequence ........................................................ 6-18 6-5. Resistance Calibration Points and Sequence .......................................................... 6-20 6-6. DC Current Calibration Points and Sequence ........................................................ 6-29 6-7. AC Current Calibration Points and Sequence ........................................................ 6-31 6-8. DC Voltage Verification Points and Sequence ...................................................... 6-39 6-9. AC Voltage Verification Points and Sequence ...................................................... 6-41 6-10. Resistance Verification Points and Sequence ........................................................ 6-45 6-11. DC Current Verification Points and Sequence ....................................................... 6-47 6-12. AC Current Verification Points and Sequence ....................................................... 6-49

8508A

viii

ix List of Figures Figure Title Page 1-1. Rear Panel - Power Input Fuse and line Power Locations ..................................... 1-12 2-1. Front Panel Displays .............................................................................................. 2-3 2-2. Front and Rear Input Terminals ............................................................................. 2-3 2-3. Sample of the Main Display ................................................................................... 2-4 2-4. 8508A Rear Panel Detail ........................................................................................ 2-7 2-5. The 8508A-LEAD Measurement Lead Kit ............................................................ 2-10 3-1. Simple Lead Connections ...................................................................................... 3-7 3-2. Twisted-Pair Cable Connections ............................................................................ 3-7 3-3. External Guard Connections .................................................................................. 3-7 3-4. Internal Guard Connections ................................................................................... 3-8 3-5. 2-Wire Measurements ............................................................................................ 3-17 3-6. 4-Wire Measurements ............................................................................................ 3-18 3-7. 4-Wire High Resistance Measurements ................................................................. 3-18 3-8. Resistance Zero Measurements .............................................................................. 3-19 3-9. Ω Guard Measurements ......................................................................................... 3-20 3-10. Internal Guard Connections ................................................................................... 3-20 3-11. PRT Connections ................................................................................................... 3-28 3-12. TruΩ Ratio Measurements ..................................................................................... 3-31 4-1. IEEE 488 Input/Output Connector ......................................................................... 4-4 4-2. 8508A Status Report Structure ............................................................................... 4-8 6-1. Equipment Connections Required for Calibration ................................................. 6-13

8508A

x

1-1 Chapter 1 Introduction and Safety Information

Title Page Introduction ........................................................................................................ 1-3 How to Contact Fluke ........................................................................................ 1-3 Unpacking and Inspection.................................................................................. 1-4 Standard Accessories ..................................................................................... 1-4 Optional Accessories ..................................................................................... 1-5 Storing and Shipping the Multimeter ................................................................. 1-6 Line Voltage ...................................................................................................... 1-6 Power Voltage Selector and Fuses ................................................................ 1-6 Changing Supply Voltage or Replacing Line Fuse ....................................... 1-6 Calibration Enable Switch ................................................................................. 1-7 System Use .................................................................................................... 1-7 Safety Considerations and Symbols ................................................................... 1-7 General Safety Summary ............................................................................... 1-7 Safety Information ............................................................................................. 1-8 Symbols ............................................................................................................. 1-10 Protection Class I ........................................................................................... 1-11 Protective Earth/Ground ............................................................................ 1-11 Do Not Operate Without Covers ............................................................... 1-11 Safe Operating Conditions ........................................................................ 1-11 Fuse Requirements .................................................................................... 1-12 Rear Panel Detail ....................................................................................... 1-12 The Power Cable and Power Supply Disconnection ................................. 1-12 Terminal Connections ............................................................................... 1-13 Measurement Category I ............................................................................... 1-13 Maintenance and Repair ................................................................................ 1-13 Moving and Cleaning .................................................................................... 1-13

8508A

Introduction and Safety Information

Introduction 1

1-3 Introduction The Fluke 8508A Reference Multimeter (hereafter "the Multimeter") is designed for the most demanding measurement applications and provides extremely high measurement precision in both stand-alone and systems applications. Chapter 1 ‘Introduction and Safety Information’ provides unpacking, storage and shipping instructions, line voltage, and safety information. Chapter 2 ‘Getting Acquainted with the Basic” provides an introduction to the front panel keys operation and rear panel connector details. Chapter 3 provides detailed access information to the full range of multimeter facilities, with suggestions for measurement techniques. Chapter 4 provides detailed information for remote control access via the IEEE 488 interface. Chapter 5 provides specification details for the multimeter. Chapter 6 provides detailed information for access to calibration menus, suggested calibration methods and verification of the multimeter.  Warning To avoid electric shock, personal injury, or death, carefully read the information under Safety Considerations before attempting to install, use, or service the Multimeter. How to Contact Fluke To contact Fluke, call one of the following telephone numbers:

8508A

Usa

Lc1 284174

Uk

Lc4 769455

Lc3 769422

Lc5 769448

Lc7 782771

Lc6 658641

Lc42

1903307 1907075 1908153 2463103 Users Manual 1673798

Introduction and Safety Information

Unpacking and Inspection 1

1-5 Optional Accessories Table 1-2. Additional Accessories for the Multimeter Description Order Number Rack Mount Kit

Y8508 1886215

Y8508S 1886232

8508A – Prt 1886194

8508A – Sprt 1886182

8508A-7000K 1886226

8508A – Lead 1886203

8508A

Introduction and Safety Information

Calibration Enable Switch 1

1-7 Calibration Enable Switch This two-position switch on the rear panel protects the instrument calibration memory. The instrument was initially calibrated at the factory and the switch covered with a calibration sticker, so the sticker and the switch should remain as delivered, until immediate recalibration is intended. If the calibration menu is selected while the calibration switch is not in the enabled position, the menu is replaced by the warning message:

Calibration Disabled

8508A

Introduction and Safety Information

Safety Information 1

1-9 • Disconnect the mains power cord before you remove the Product covers. • Remove the input signals before you clean the Product. • Use only specified replacement parts. • Use only specified replacement fuses. • The mains power service must be rated for 16 A, and if the mains power cord is internally fused, a 10 A fuse must be fitted in the mains power cord plug. • Have an approved technician repair the Product. • When the cover is removed, voltages more than 1.5 KV can be present. • Properly terminate the sense leads to prevent exposure to hazardous voltages on the sense terminals. The voltage sense terminals are at output voltage when the two-wire function is set. • Never touch a lead or terminal on the Product when a dangerous voltage is present. • Do not use low voltage spade-terminated leads to connect to a hazardous voltage (>32 V ac rms or >42 V pk). A general purpose probe kit is supplied with the Product for safe measurement at higher voltages. • Do not touch exposed metal on banana plugs, they can have voltages that could cause death. • Do not use test leads if they are damaged. Examine the test leads for damaged insulation and measure a known voltage. • Use the correct terminals, function, and range for measurements. • Keep fingers behind the finger guards on the probes. • Connect the common test lead before the live test lead and remove the live test lead before the common test lead. • Remove signal connections before the protective ground connection is removed. For example, the mains power cord must be connected when the signal leads are connected. • Do not connect or disconnect signal leads while they are connected to a hazardous voltage or current source. • Disconnect power and discharge all high-voltage capacitors before you measure resistance, continuity, capacitance, or a diode junction. • Before the Product is connected to a circuit to make a current measurement, check the fuses on the Product and turn off the power to the circuit. • Limit operation to the specified measurement category, voltage, or amperage ratings. • Do not connect measurement probes directly to mains. • Complete safety tests after a part replacement to make sure the Product is safe. • Do not connect an external capacitance greater than 50 nF to the Product terminals.

8508A

Cat Ii

Cat Iii

Cat Iv

Introduction and Safety Information

Symbols 1

1-11 Protection Class I Protective Earth/Ground The Multimeter must be operated with a Protective Earth/Ground connected via the power cable's protective earth/ground conductor. The Protective Earth/Ground connects to the instrument before the line & neutral connections when the supply plug is inserted into the power socket on the back of the instrument.  Warning To avoid possible electric shock, personal injury, or death: • Ensure that no interruption of the protective ground conductor inside or outside the instrument has occurred. Any interruption of the protective ground is likely to make the instrument dangerous. • Make signal connections to the instrument after making the protective ground connection. • Remove signal connections before removing the protective ground connection, i.e. the power cable must be connected whenever signal leads are connected. Do Not Operate Without Covers  Warning To avoid possible electric shock, personal injury, or death, do not operate the instrument with its covers removed. The covers protect users from live parts, and unless otherwise stated, must only be removed by qualified service personnel for maintenance and repair purposes. Removing the covers may expose voltages in excess of 1.5 kV peak. Safe Operating Conditions  Warning To avoid electric shock or fire hazard, do not apply to or subject the Multimeter to any condition that is outside specified range. See Chapter 5 of this manual for detailed instrument specifications and operating conditions. Only operate the Multimeter within the manufacturer's specified operating conditions. Examples of operating condition specifications examples that must be considered include: • Ambient temperature • Ambient humidity • Power supply voltage & frequency • Maximum terminal voltages or currents • Altitude • Ambient pollution level • Exposure to shock and vibration Caution To avoid possible damage to the Multimeter, consider direct sunlight, radiators and other heat sources when assessing ambient temperature. Before connecting the Multimeter to the supply, make sure that ac supply voltage connector on the rear panel is set to the correct voltage and that the correct fuses are fitted.

8508A

Iec 127 (Ul/Csa)

115 Vac,

230 Vac

Th

1.25 A (2 A) @ 250 V

S505-1.25-R

215 1.25P

5Ht 1.25-R

Iec 127 (Ul / Csa)

Fh

1.6 A (2 A)@ 250 V

T1.25Ah 250V

Line Voltage

Selection

Iec127

T1.25Ah 250V

Line Voltage

100V - 120V

200V - 240V

adj019f.eps Figure 1-1. Rear Panel – Power Input Fuse and line Power Locations The Power Cable and Power Supply Disconnection The intended power supply disconnect device is the ON/OFF switch that is located on the Multimeter's rear panel. The ON/OFF switch must be readily accessible while the instrument is operating. If this operating condition cannot be met, the power cable plug or other power disconnecting device must be readily accessible to the operator.  Warning To avoid electric shock and fire hazard, make sure that the power cable is not damaged, and that it is adequately rated against power supply network fusing. If the power cable plug is to be the accessible disconnect device, the power cable must not be longer than 3 meters.

Introduction and Safety Information

Symbols 1

1-13 Terminal Connections Make sure that the instrument is correctly grounded (earth ground) via the power cable before and while any other connection is made. Measurement Category I Measurement and/or guard terminals are designed for connection at Measurement Category I.  Warning To avoid electric shock and fire hazard, do not connect the Multimeter terminals directly to the ac line power, to an ac line power current transformer, or to any other voltage or current source that may (even temporarily) exceed the instrument's peak ratings.  Warning

To avoid injury or death, do not connect or disconnect signal leads while they are connected to a hazardous voltage or current source. Make sure that signal leads are in a safe condition before you handle them. This instrument can deliver a lethal electric shock. Never touch any lead or terminal unless you are absolutely certain that no dangerous voltage is present. Maintenance and Repair  Warning

For protection against injury and fire hazard, use only manufacturer supplied parts that are relevant to safety. Perform Safety tests after replacing any part that is relevant to safety. Observe all applicable local and/or national safety regulations and rules while performing any work. First disconnect the instrument from all signal sources, then from the ac line supply before removing any cover. Any adjustment, parts replacement, maintenance or repair should be carried out only by the manufacturer's authorized service personnel. Moving and Cleaning First disconnect the Multimeter from all signal sources, then from the AC line power before moving or cleaning. Use only a damp, lint-free cloth to clean fascia and case parts.

8508A

2-1 Chapter 2 Getting Acquainted with the Basics

Title Page Introduction .......................................................................................................... 2-3 Input Terminals .................................................................................................... 2-3 The Front Panel Displays ..................................................................................... 2-4 Front Panel Keys .................................................................................................. 2-4 Soft-Keys and Manual Conventions ................................................................ 2-4 Numeric Keyboard .......................................................................................... 2-5 Exiting a Menu ................................................................................................ 2-5 Major Function Keys ....................................................................................... 2-5 Direct Action Keys .......................................................................................... 2-6 Mode Keys....................................................................................................... 2-6 Rear Panel ............................................................................................................ 2-7 Labels .............................................................................................................. 2-7 Fuses ................................................................................................................ 2-7 Voltage Selector .............................................................................................. 2-7 Power Input and Power Switch ....................................................................... 2-7 Calibration Switch ........................................................................................... 2-7 Rear Panel Connectors and Pin Designations ...................................................... 2-8 Rear Inputs....................................................................................................... 2-8 External Trigger Input ..................................................................................... 2-8 IEEE 488 Input/Output .................................................................................... 2-8 Power-On Configuration ...................................................................................... 2-8 The 8508A-LEAD Measurement Lead Kit .......................................................... 2-9

8508A

Getting Acquainted with the Basics

Introduction 2

2-3 Introduction Chapter 2 introduces the front and rear panel features of the 8508A Reference Multimeter (hereafter, referred to as the Multimeter). Figure 2-1 shows the Multimeter's front panel controls, indicators, and connectors.

adj002f.eps Figure 2-1. Front Panel Displays Input Terminals  Warning To avoid electric shock, personal injury, or death, never touch any lead or terminal on the Multimeter unless you are absolutely certain that no dangerous voltage is present. The 8508A Multimeter has only front terminals. The 8508A/01 has both front and rear panel input terminals (Figures 2-2). Select either, or Scan both from the Input menu or via IEEE-488 remote control. For maximum input limits, refer to product specifications in Chapter 5.

adj013f.eps

adj014f.eps Figure 2-2. Front and Rear Input Terminals Three pairs of 4 mm ‘banana’ terminals are fitted on the left of the front panel and, as an option, on the right of the rear panel . Their functions are as follows: INPUT 2 wire

Sense 4Wire Ω, Acv

Hi

Hi

Lo

Lo

Ohms Low (4wire)

A

Guard

8508A

adj360f.eps Figure 2-3. Sample of the Main Display Front Panel Keys There are four types of keys (Figure 2-1) on the front panel: • The major measurement function keys:  • The mode keys:  • Direct action keys that immediately initiate an action or set a state:  • The "soft-keys" point to a menu label on the display above, indicating the operation and setting of the Multimeter:  System messages may appear to clarify settings or operations. Soft-Keys and Manual Conventions

adj015f.eps Soft-Keys • A Menu softkey accesses a new menu. In this manual, a Menu soft-key is shown as displayed or in a Helvetica- regular font: Example:  or Resl • A Toggle softkey enables or disables a selection The enabled selection is indicated with a  symbol. In this manual, a Toggle soft-key is shown as displayed or in Helvetica-italic- underline font : Example:  or Filt • A Choice softkey chooses a state (e.g., selects a range) or triggers a direct action. The selected state or action is indicated as displayed with a  symbol.

Getting Acquainted with the Basics

Front Panel Keys 2

2-5 In this manual, a Choice soft-key is shown as displayed or in Helvetica-underline font: Example:  or 100mV Numeric Keyboard

adj012f.eps Numeric Keyboard The operation of the numeric keys is enabled for appropriate menus. The active keys are:  numerals 0 to 9.  decimal point  polarity  for exponent  for backspace  to enter the last reading taken  to confirm the numeric entry  to abort the numeric entry. When the numeric keyboard is active other keys are locked out. For some operations the two alpha selection keys are enabled along with the numeric keys.  selects the alpha characters (upper case only) and cylces A through Z.  enters the selected character and moves the entry point one character to the right. Exiting a Menu You can generally exit from any menu by pressing a measurement function key or a mode key. For those menus where the numeric or alpha numeric keyboard is active, exit by pressing either Enter or Quit. For some menus, a special soft key permits exit by a single keystroke. Major Function Keys

adj016f.eps Each measurement function has a CONFIG (Configuration) menu, from which you can select function-dependent parameters such as resolution and filter settings. Once set, the instrument remembers the function dependant parameters until you change it or turn the Multimeter off.

8508A

adj017f.eps Direct Action Keys Press to disable internal triggers and enable all external trigger sources. The Ext annunciator on the main display is lit. An external trigger for a measurement may be generated either by pressing the Sample key, by sending an appropriate trigger command via the IEEE-488 interface, or by a falling edge (TTL) at the External Trigger input on the rear panel. Press to trigger a single-shot measurement if the Multimeter is in Ext’trig mode. All measurements triggered using the Sample key are subject to the standard internal time delays before A-D conversion. These are listed on Table 4-2 and 4-3. During the measurement the Busy annunciator on the main display is lit.

Note

Getting Acquainted with the Basics

Rear Panel 2

2-7 Rear Panel

Rl1 Pp0 Dc1 Dt1 C0 E2

Trig

5V Pk Max

Rear Input

Current

Fuse.

F1.6Ah,

250V

Iec127

Calibration

Enable

Disable

T1.25Ah 250V

Line Voltage

Selection

Iec127

Listed. 3012749

Note

T1.25Ah 250V

Conforms To Ul Std. Ul61010-1:2004

Aux Earth (Ground)

Made In Uk

Fluke Corporation

No User Serviceable Parts Contained. Do Not Remove The Covers.

Refer Service To Qualified Personnel.

Line Voltage

100V - 120V

200V - 240V

C1

adj018f.eps Figure 2-4. 8508A Rear Panel Detail Labels Attached to the rear panel is the identification label for the instrument, and a modification strike label. Fuses  Power Fuse: Located in the fuse drawer which is part of the integrated module for power input and voltage selection.  Rear Input Current Fuse: Protects the current measuring circuitry when using the rear terminals for signal input. Warning To avoid damage to the Multimeter, or shock, injury, or death, use ONLY fuses with the amperage, interrupt, voltage, and speed ratings specified. Refer to the safety information and "Fuse Requirements" in Chapter 1 of this manual. Voltage Selector The power line voltage selector block is located behind the fuse block drawer, and adapts the instrument to either 115V or 230V line inputs. Power Input and Power Switch The power input socket and power ON/OFF switch are part of the integrated module for power input and voltage selection. Power on default configuration is listed later in this chapter. Calibration Switch Access to calibration mode is enabled (or restricted) by the rear panel calibration switch. Setting the switch to ENABLE will allow access to the calibration mode via the front panel CAL key and the CALIBRATION menu, and will also enable the remote IEEE-488 interface calibration commands. The calibration switch should always be set to DISABLE on completion of any calibration operations. Applying an integrity seal or calibration sticker to cover the rear panel Calibration switch is a convenient way to ensure the security of calibration and prevent unauthorized access to the switch.

8508A

Dcv

Getting Acquainted with the Basics

The 8508A-LEAD Measurement Lead Kit 2

2-9 The 8508A-LEAD Measurement Lead Kit  Warning

Safe Use Of Measurement Leads

8508A

adj388f.eps Figure 2-5. The 8508A-LEAD Measurement Lead Kit

3-1 Chapter 3 Making Measurements

Title Page Introduction .......................................................................................................... 3-3 Making Connections to the Multimeter -- General Guidelines ............................ 3-4 Using the Measurement Functions ....................................................................... 3-5 DC Voltage ...................................................................................................... 3-5 Measuring DC Voltage .................................................................................... 3-7 Making Input Connections .......................................................................... 3-7 AC Voltage ...................................................................................................... 3-8 Measuring AC Voltage .................................................................................... 3-11 Induced Interference .................................................................................... 3-11 Common Mode Rejection ........................................................................... 3-11 Lead Considerations .................................................................................... 3-11 Resistance ........................................................................................................ 3-11 High Voltage Ohms ......................................................................................... 3-13 True Ohms ....................................................................................................... 3-15 Measuring Resistance ...................................................................................... 3-17 2-Wire Measurements ................................................................................. 3-17 4-wire Measurements .................................................................................. 3-17 4-wire High Resistance Measurements ....................................................... 3-18 4-wire Resistance Zero ................................................................................ 3-18 Ω Guard ....................................................................................................... 3-19 DC Current ...................................................................................................... 3-21 Measuring DC Current .................................................................................... 3-22 AC Current ...................................................................................................... 3-23 Measuring AC Current .................................................................................... 3-24 Temperature ..................................................................................................... 3-25 Measuring Temperature ................................................................................... 3-28 Multimeter Inputs ................................................................................................ 3-29 Input ................................................................................................................. 3-29 Using the INPUT Key ..................................................................................... 3-29 SCAN OPERATIONS ..................................................................................... 3-30 Tru Ohms Ratio ........................................................................................... 3-31 Monitoring Modes ............................................................................................... 3-32 Monitor Key .................................................................................................... 3-32 Displaying Signal Frequency........................................................................... 3-32 Displaying Standard Deviation ........................................................................ 3-32 Devn Menu .................................................................................................. 3-32

8508A

Making Measurements

Introduction 3

3-3 Introduction Warning The Multimeter can deliver a lethal electric shock. To avoid electric shock, personal injury, or death, carefully read the information under "Safety Considerations" in Chapter 1 before attempting to install, use, or service the 8508A Reference Multimeter. A " Warning" statement identifies conditions or practices that could result in injury or death. A " Caution" statement identifies conditions or practices that could result in damage to the Multimeter or equipment to which it is connected. Chapter 3 explains in detail how to use the 8508A Reference Multimeter's (hereafter “the Multimeter”) measurement functions and operating modes. It is organized to provide easy access to the following functions and modes. Functions DC Voltage AC Voltage Resistance DC Current AC Current Temperature Modes Input Control Monitoring Math Utility Clear Test The topics covered in Chapter 3 include: making connections, input limits, types of configurations, accessing and selecting measurement modes, and calculations available. Product specifications and operating limits are in Chapter 5. See Chapter 6 for calibration menus and the recommended calibration routines. All error messages displayed by the Multimeter's front panel or generated by the IEEE 488 system bus are collected and described in Appendix A. Before proceeding make sure that the Multimeter has been properly installed and prepared for operation as described in Chapter 1.  Warning The Multimeter can deliver a lethal electric shock. To avoid possible electric shock, personal injury, or death: • Ensure that no interruption of the protective ground conductor inside or outside the instrument has occurred. Any interruption of the protective ground is likely to make the instrument dangerous. • Never touch any lead or terminal unless you are absolutely certain that no dangerous voltage is present.

8508A

Ptfe.

Making Measurements

Using the Measurement Functions 3

3-5 Using the Measurement Functions If you are unfamiliar with the front panel controls, review the relevant sections of Chapter 2. DC Voltage Press DCV key to display the DCV menu.

adj055f.eps DCV Menu  This function provides both 2-wire and 4-wire measurements, in decade ranges from 200mV to 200V and a 1kV range.  To cancel autoranging and enter a manually selected range, press any range selection or the Auto softkey. The Multimeter enters the selected range or reverts to the auto-selected range. DCV Configuration (4 wire Sense, Resolution, LP Filtering and Fast) Press the Config key to see the DCV CONFIG menu:

adj056f.eps DCV Configuration Menu  Allows operation with calibrators which provide a remote 4 wire sensing capability by providing connections between INPUT HI and SENSE HI and between INPUT LO and SENSE LO. The 4wV annunciator in the left-hand display indicates that 4-wire sensing is active.  Provides selection of the numerical resolution for subsequent readings.  Controls a three-pole analog filter for increased noise rejection. The Filter annunciator on the left-hand display indicates that the filter is active and indicates its cut-in frequency.  Select a higher read rate. This will result in an increase in uncertainty due to noise. The Fast annunciator on the left-hand display indicates that the higher read rate is active.

8508A

adj058f.eps DCV Resolution Menu 5 5-1/2-digits resolution 6 6-1/2-digits resolution 7 7-1/2-digits resolution 8 8-1/2-digits resolution To revert to the DCV CONFIG menu, press the CONFIG key. To revert to the DCV menu from either DCV RESL or DCV CONFIG, press the DCV key. Refer to Table 3-2 for the ADC integration times applicable to the various resolution and Fast On/Off settings. Table 3-2. Analog to Digital Converter (ADC) signal integration times Function Resolution Integration Time Fast On Fast Off DCV, DCI1, Ohms, True Ohms,

Prt2

1 Plc

1 Plc

16 Plc

64 Plc

64 Plc

64 Plc

Dcv

Config

Toggle

Toggle

On/Off

On/Off

adj054f.eps DC Voltage Menu Tree

Making Measurements

Using the Measurement Functions 3

3-7 Measuring DC Voltage Making Input Connections Simple Lead Connection For the majority of applications the simple lead connection without external guard will be adequate. See Figure 3-1.The disadvantage of this simple arrangement is that the connecting leads can form a loop. If a stray alternating magnetic field (e.g., from the line transformer of a neighboring instrument) passes through the loop, it will behave as a single-turn secondary winding inducing unwanted AC voltages into the measuring circuit. Use of a twisted-pair will reduce the loop area and adjacent twists will cancel any induced voltages. If problems with stray pick-up are encountered, it is recommended that a shielded twisted-pair cable be used with the screen connected to the Lo terminal at the source as shown in Figure 3-2.

Hi

Lo

Guard

adj059f.eps Figure 3-1. Simple Lead Connections Hi Lo Guard Vcm Gu Lo Hi

adj060f.eps Figure 3-2. Twisted-Pair Cable Connections Common Mode Rejection - Use of External Guard Connection Use the Guard terminal with External Guard selected when the source to be measured presents an unbalanced impedance to the measuring terminals, and common mode voltages are present. Regardless of how the Hi and Lo terminals are connected, the Guard terminal should be referred to the source of common mode voltage, as shown in Figure 3-3. This ensures that errors caused by common mode currents in the measuring circuit are minimized by providing a separate common mode current path. Lo Gu Vcm 2 Vcm 1

C1

R1

C2

R2

C3

R3

R1, C1

R2, C2

R3, C3

adj061f.eps Figure 3-3. External Guard Connections

8508A

(Dcv & I, Acv & I)

0 V

adj062f.eps Figure 3-4. Internal Guard Connections Selecting External Guard (ExGd) See Figure 3-3 for a description of External Guard Connections. To select External Guard:

adj064f.eps INPUT Menu

adj066f.eps ACV Menu  This function provides both 2-wire and 4-wire measurements, in decade ranges from 200mV to 200V and a 1kV range.  To cancel autoranging and enter a manually selected range, press any range selection or the Auto softkey. The Multimeter enters the selected range or reverts to the auto-selected range.

Making Measurements

Using the Measurement Functions 3

3-9 ACV Configuration (4 wire Sense, Resolution, RMS Filtering, Transfer mode, DC- Coupled and Spot Frequency) Press the Config key to see the ACV CONFIG menu.

adj067f.eps ACV CONFIG Menu  Allows operation with calibrators which provide a remote 4 wire sensing capability by providing, at an internal reference plane within the DMM, connections between INPUT HI and SENSE HI and between INPUT LO and SENSE LO. Use of an internal reference plane can be helpful in 4wire AC, AC transfer, or 4wire AC – DC transfer applications. The 4wV annunciator in the left-hand display indicates that 4-wire sensing is active.  Provides selection of the resolution for subsequent readings.  Provides selection of various filters for the RMS converter, allowing measurements to be made down to the chosen filter frequency. One of four filters is always in circuit. The 40Hz filter is the default selection at power on. The Filter annunciator on the left-hand display indicates that the filter is active and indicates its frequency.  Controls the internal electronic AC-DC transfer for AC measurement, improving linearity and temperature performance at the expense of read rate. Tfer on is the default selection at power on. The Tfer annunciator on the left-hand display indicates that internal AC- DC transfer is active.  DC couples the input circuitry to include DC signal components in the AC measurement when selected. Note DC-coupled should be selected for signal frequencies less than 40 Hz. The DC coupled annunciator in the left-hand display indicates active state.  Selects the Spot Frequency measurement mode, where calibration constants derived for up to six previously calibrated spots (Sp1 thru 6) are applied for signal frequencies within ± 10 % of a spot frequency. This can be used to significantly reduce flatness errors in Sine Wave (low crest factor) measurement applications. The Spot annunciator on the left-hand display indicates that Spot corrections are active.

8508A

adj068f.eps ACV RESL Menu 5 5-1/2-digits resolution 6 6-1/2-digits resolution

To revert to the ACV CONFIG menu, press the Config key. ACV Filter Press the Filt key to see the ACV FILT menu:

adj069f.eps ACV FILT Menu The ACV FILT menu allows selection of one of four RMS filters. The indicated value is the lowest signal frequency that can be measured without degradation of accuracy and excessive reading variation. The default setting at power on is 40 Hz. Note Measurement results are invalid when using internal triggers in Transfer mode with the 1 Hz filter selected. For valid results, use Ext Trig and Sample, or trigger via the IEEE-488 interface. AC Voltage - Movement between Menus

Acv

Config

Toggle

Toggle

On/Off

On/Off

Toggle

adj070f.eps AC Voltage Menu Tree

Making Measurements

Using the Measurement Functions 3

3-11 Measuring AC Voltage Induced Interference If inference signals are present or lead pickup takes place during AC measurements, any induced interfering signals will combine with the signal being measured and result in measurement errors. In some circumstances, it may be possible to filter out the unwanted external signals, but it is generally more effective to reduce the interference before it is induced. This is most easily accomplished by operating in a quiet environment, e.g., using a screened cage and, if possible, using twisted or shielded measurement leads as discussed below. Common Mode Rejection The principles of external guarding, outlined in the description of DC voltage measurement, apply generally to AC voltage measurement. For AC a further advantage can be gained by using the external guard as a shield for the input leads. Lead Considerations In all cases, AC voltage measurement accuracy is improved by shortening the leads to the minimum practical length to reduce lead capacitance, lead inductance and loop area. Shielded twisted pair leads are recommended for low frequency measurements and coaxial leads are recommended for low and high frequency measurements. Users should take care to avoid measurement errors from the interaction of lead capacitance and inductance with any source output impedance. Additional information and guidance is available in the Fluke publication Calibration: Philosophy in Practice

(Isbn 0-9638650-0-5).

adj073f.eps OHM Menu  This function provides both 2-wire and 4-wire measurements, in decade ranges from 2 Ω to 2 GΩ.  To cancel autoranging and enter a manually selected range, press any range selection or the Auto softkey. The Multimeter enters the selected range or reverts to the auto-selected range.

8508A

adj074f.eps OHM CONFIG Menu  Provides selection of the resolution for subsequent readings.  Controls a single-pole analog filter for increased noise rejection. The Filter annunciator on the left-hand display indicates that the filter is active. Note The pole or time constant of the filter is formed by a Capacitance of 22 nF across the resistor under test.  Select a higher read rate. This will result in an increase in uncertainty due to noise. The Fast annunciator on the left-hand display indicates that the higher read rate is active.  Controls the measurement currents. The current in use for the selected range is indicated in the left-hand display together with the maximum voltage that will appear across the measured resistance at full scale. With LoI selected the behaviour of Auto Ranging is modified such that the Multimeter will only range up to the 20 MΩ Range.

Note Low Current resistance measurement may be desirable to reduce any self-heating in the device under test or to avoid conduction of any parallel semi-conductor junction.  Selects 4-wire resistance measurements in which the stimulus current is fed through the test resistance from the instrument's INPUT Hi and Lo terminals. The resulting potential difference is sensed by the SENSE Hi and Lo terminals. Otherwise all measurements are 2-wire, current being sourced and potential differenced sensed from the INPUT Hi and Lo terminals. The 4wΩ annunciator in the left-hand display indicates that 4 wire sensing is active.

Making Measurements

Using the Measurement Functions 3

3-13 OHMS Resolution Press the Resl key to see the OHMS RESL menu:

adj075f.eps OHM RESL Menu 5 5-1/2-digits resolution 6 6-1/2-digits resolution 7 7-1/2-digits resolution 8 8-1/2-digits resolution Refer to Table 3-2 for the ADC integration times applicable to the various resolution and Fast On/Off settings. To revert to the OHMS CONFIG menu, press the Config key. Ohms - Movement between Menus

Config

Toggle

Toggle

Toggle

On/Off

adj076f.eps Ohms Movement Between Menu High Voltage Ohms Press the Ω PLUS key to see the expanded Ohms selection for True Ohms function and the High Voltage Ohms function. Press HiVΩ key to see the HiVΩ menu:

adj077f.eps

adj078f.eps HiVΩ Menu The function provides both 2-wire and 4-wire measurements of resistance, in decade ranges from 20 MΩ to 20 GΩ. The measurement is performed at High Voltage using a current source with high compliance. The resulting increase in Current through the unknown resistor is valuable to the reduction of leakage and bias current uncertainties. The function may also be used alongside the normal Ohms function to determine Voltage Coefficient in the unknown resistor.

8508A

Danger Of Lethal Electric Shock

Caution

adj079f.eps HiVΩ CONFIG Menu  Provides selection of the resolution for subsequent readings.  Controls a single-pole analog filter for increased noise rejection. The Filter annunciator on the left-hand display indicates that the filter is active. Note The pole or time constant of the filter is formed by a Capacitance of 22 nF across the resistor under test.  Select a higher read rate. This will result in an increase in uncertainty due to noise.  Selects 4-wire resistance measurements in which the stimulus current is fed through the test resistance from the instrument's INPUT Hi and Lo terminals. The resulting potential difference is sensed by the SENSE Hi and Lo terminals. Otherwise all measurements are 2-wire, current being sourced and potential difference being sensed from the INPUT Hi and Lo terminals.

Making Measurements

Using the Measurement Functions 3

3-15

HIVΩ Resolution Press the Resl key to see the HIΩ RESL menu:

adj080f.eps HiVΩ RESL Menu 5 5-1/2-digits resolution 6 6-1/2-digits resolution 7 7-1/2-digits resolution 8 8-1/2-digits resolution Refer to Table 3-2 for the ADC integration times applicable to the various resolution and Fast On/Off settings. To revert to the HiVΩ CONFIG menu, press the Config key. To revert to the HiVΩ menu from either HiVΩ RESL or HiVΩ CONFIG, press the HiVΩ menu key. HIVΩ - Movement between Menus

adj085f.eps HiVΩ Movement Between Menu True Ohms

adj081f.eps TruΩ Menu Press the Ω PLUS key to see the expanded Ohms selection for True Ohms function and the High Voltage Ohms function. Press the Tru Ω key for the Tru Ω menu. The TruΩ mode takes two measurements per reading. The second measurement is made with the current reversed relative to the first measurement. The two measurements are combined to eliminate the effects of any external EMFs that may be present.  This function provides only 4-wire measurements of resistance, in decade ranges from 2 Ω to 20 kΩ. The stimulus current is fed through the test

8508A

adj082f.eps TRUΩ CONFIG Menu Provides selection of the resolution for subsequent readings. Select a higher read rate. This will result in an increase in uncertainty due to noise.  Controls the measurement currents. The current in use for the selected range is indicated in the left-hand display together with the maximum voltage that will appear across the measured resistance at full scale. TRUΩ Resolution Press the Resl key to see the TRUΩ RESL menu:

adj083f.eps TRUΩ RESL Menu 5 5-1/2-digits resolution 6 6-1/2-digits resolution 7 7-1/2-digits resolution 8 8-1/2-digits resolution Refer to Table 3-2 for the ADC integration times applicable to the various resolution and Fast On/Off settings. To revert to the TRUΩ CONFIG menu, press the Config key.

Making Measurements

Using the Measurement Functions 3

3-17 TRUΩ - Movement between Menus

adj086f.eps TRUΩ Movement Between Menu Measuring Resistance 2-Wire Measurements For many applications the simple 2-wire arrangement will be adequate. See Figure 3-5. However, the value displayed will include the resistance of the connecting leads. Use a shielded twisted-pair cable, preferably of PTFE insulation, to reduce induced voltages, induced charge and shunt leakage resistance, particularly where Rx is high. 2-wire resistance measurement is not available when in TruΩ mode and is not well suited to use in the 2 Ω range. In the latter case zero compensation for lead and internal resistance contributions may limit full-scale readout. 2-wire measurements above 1.5 Ω should be made using higher ranges.

Input Hi

Input Hi

Input Lo

Input Lo

Guard

adj091f.eps Figure 3-5. 2-Wire Measurements 4-wire Measurements With a 4-wire connection the lead resistances have negligible effect and only the value of Rx is displayed.

8508A

Sense Hi

Sense Hi

Sense Lo

Sense Lo

Guard

Input Hi

Input Hi

Input Lo

Input Lo

adj092f.eps Figure 3-6. 4-Wire Measurements 4-wire High Resistance Measurements When making very high resistance measurements above about 1 MΩ, a metal screen can be wrapped around the resistor to reduce noise, usually caused by charge injection. Connecting the GUARD terminal to the screen will intercept leakage via the screen (in parallel with the unknown resistor). The resistor under test should not be grounded, as this will make the measurement noisier.

Sense Hi

Sense Hi

Sense Lo

Sense Lo

Guard

Input Hi

Input Hi

Input Lo

Input Lo

Guard

adj093f.eps Figure 3-7. 4-Wire High Resistance Measurements 4-wire Resistance Zero For accurate measurements of resistance it is essential that a correctly connected zero source be used when performing an Input-Zero operation before making a series of measurements. The preferred arrangement shown in Figure 3-8 ensures that thermal and induced EMF effects, and bias current effects, associated with the multimeter and the measurement cables are eliminated. Two precision 4wire short accessories are supplied as standard within the 8508A – LEAD leadkit. Fitted over the Input Hi, Input Lo, Sense Hi and Sense Lo terminals these provide a convenient means of zeroing the 8508A inputs at the terminals. Use of the 4-wire short device at the multimeter terminals does not address potential sources of error within measurement cables.

Making Measurements

Using the Measurement Functions 3

3-19

Sense Hi

Sense Hi

Sense Lo

Sense Lo

Guard

Guard

Input Hi

Input Hi

Input Lo

Input Lo

adj094f.eps Figure 3-8. 4-Wire Resistance Zero Measurements Ω Guard In the resistance function with Ext Grd selected the Guard terminal functions as Ω Guard. Using the Guard terminal as Ω Guard, the Ω Guard feature can be used to make ‘in-circuit’ resistance measurements by guarding out parallel resistance paths so that only the value of Rx will be displayed. Similarly, Ω Guard can be used to reduce the settling time if Rx is shunted by any capacitance and a suitable tapping point is available. The connections for making Ω Guard measurements are shown in Figure 3-9. Selection of External Guard is required. Table 3-3. Minimum Guard Resistances Range Minimum value for Ra and Rb

2 Ω, 20 Ω

200 Ω

200 Ω

20 Mω, 200 Mω, 2 Gω, 20 Gω

Providing that Ra and Rb are greater than the values shown in Table 3-3. Minimum Guard Resistances, and the Ω Guard resistance (Rg) is less than 1 Ω; the actual value can be calculated from the displayed value Rd by: Rx = Rd x (1 + E) Deviation fraction ‘E’ can be found within 1 % by the simplified formula: E = (Rd x Rg) / (Ra x Rb) (Where Rg is the Ω Guard lead-resistance from the junction of Ra and Rb) Example: If Rd = 100 Ω, Rg = 1 Ω, Ra = Rb = 10 kΩ, then the value of E is given by: E = (100 x 1) / (10 k x 10 k) = 10 -6 (1 ppm of readings) The value of Rx is thus given by: Rx = 100 x (1 + 10 -6) Ohms, = 100.0001 Ohms

8508A

Sense Hi

Sense Hi

Sense Lo

Sense Lo

Input Hi

Input Hi

Input Lo

Input Lo

Guard

Guard

adj095f.eps Figure 3-9. Ω Guard Measurements Internal Guard Connections External Guard not selected: In the Ohms or PRT Functions the Guard terminals on the front and rear panels are isolated from each other and from any internal connection. The internal guard shields and tracks are connected directly to the internal 0 V. External Guard selected: In the Ohms or PRT Functions selecting the External Guard provides an Ohms Guard function. The internal guard shields, tracks, and the selected front or rear Guard terminal are connected to the internal 0 V. Guard terminal front External Guard Internal Guard and External Guard (OHMS and PRT) Front Guard terminal rear Internal Guard External Guard

(Dcv & I, Acv & I)

0 V

adj062f.eps Figure 3-10. Internal Guard Connections Selecting External Guard (ExGd) See Figure 3-9 for connections when using the Ω Guard feature. To select External Guard:

adj064f.eps INPUT Menu

Making Measurements

Using the Measurement Functions 3

3-21 DC Current Press the DCI key to show the DCI menu.

adj097f.eps DCI Menu  This function provides measurements, in decade ranges from 200μA to 20A. (NOTE: the 20A range is only available on the front terminals. The front current terminal is not fused.)  To cancel autoranging and enter a manually selected range, press any range selection or the Auto softkey. The Multimeter enters the selected range or reverts to the auto-selected range. DCI Configuration (Resolution, LP Filter and Fast) Press the Config key to see the DCI CONFIG menu. Resl is a menu key; Filt and Fast are toggle keys.

adj098f.eps DCI Configuration Menu  Provides selection of the resolution for subsequent readings.  Controls a three-pole analog filter for increased noise rejection. The Filter annunciator on the left-hand display indicates that the filter is active and indicates its cut-in frequency.  Select a higher read rate. This will result in an increase in uncertainty due to noise. The Fast annunciator on the left-hand display indicates that the higher read rate is active. DCI Resolution Press the Resl key to see the DCI RESL menu:

adj099f.eps DCI RESL Menu 5 5-1/2-digits resolution 6 6-1/2-digits resolution 7 7-1/2-digits resolution Refer to Table 3-2 for the ADC integration times applicable to the various resolution and Fast On/Off settings. To revert to the DCI CONFIG menu, press the Config key.

8508A

Dci

adj100f.eps DCI Movement Between Menu Measuring DC Current Insert the Multimeter in the current path via its INPUT A and INPUT Lo terminals, so that conventional current flows from the source Hi into the Multimeter's A terminal and back to the source Lo out of the Lo terminal. Similar connection considerations are required for DC current measurement as for DC voltage measurement. Use shielded twisted-pair cable to reduce induced interference signals, and connect Guard to the source of common mode voltage, to provide a separate common mode current path.  Warning

High Current Flow

Making Measurements

Using the Measurement Functions 3

3-23 AC Current Press the ACI key to show the ACI menu:

adj101f.eps ACI Menu  This function provides measurements, in decade ranges from 200μA to 20A. (NOTE: the 20A range is only available on the front terminals. The front current terminal is not fused.)  To cancel autoranging and enter a manually selected range, press any range selection or the Auto softkey. The Multimeter enters the selected range or reverts to the auto-selected range. ACI Configuration (Resolution, RMS Filtering and DC Coupled) Press the Config key to see the ACI CONFIG menu:

adj102f.eps ACI CONFIG Menu  Provides selection of the resolution for subsequent readings.  Provides selection of various filters for the RMS converter, allowing measurements to be made down to the chosen filter frequency. One of four filters is always in circuit. The 40Hz filter is the default selection at power on. The Filter annunciator on the left-hand display indicates that the filter is active and indicates its frequency.  Controls the measurement-coupling configuration. Note DC-coupled should be selected for signal frequencies less than 40 Hz.

The DC coupled annunciator in the left-hand display indicates active state. ACI Resolution Press the Resl key to see the ACI RESL menu:

adj103f.eps ACI RESL Menu This menu offers the following resolution choices: 5 5-1/2-digits resolution 6 6-1/2-digits resolution To revert to the ACI CONFIG menu, press the Config key.

8508A

adj104f.eps ACI Filt Menu The ACI FILT menu allows selection of one of four RMS filters. The indicated value is the lowest signal frequency that can be measured without degradation of accuracy or excessive reading variation. AC Current - Movement between Menus

Aci

adj100f.eps ACI Movement Between Menu Measuring AC Current Insert the Multimeter in the current path via its A and Lo terminals. Similar connection considerations are required for AC current measurement as for AC voltage measurement. Use shielded twisted pair cable to reduce induced interference signals, and connect Guard to the source of common mode voltage via the screen, to provide a separate common mode current path. The 8508A is designed to minimise the burden (compliance) voltage generated when making current measurements, thus improving measurement accuracy. However, it is recommended that leads of the minimum practical length be used to reduce lead capacitance, lead inductance and loop area.  Warning

High Current Flow

Making Measurements

Using the Measurement Functions 3

3-25 Note Lead Impedance - When making AC current measurements pay particular attention to the lead impedance, especially lead capacitance at high frequencies on the lower current ranges. (See "Measuring AC Voltage" earlier in this chapter.) Note Maximum Input Current capability and protection - The front input terminals may be used to measure currents up to 20 A. The front input A terminal protection is automatic and self-resetting, and does not interrupt current flow. Damage is likely to occur if more than 20 A is applied. The Rear input terminals may be used to measure currents up to 2 A only. The rear input A terminal is protected by a fuse mounted on the rear panel. Temperature The 8508A provides a temperature readout by measuring the resistance of the connected PRT or SPRT probe, and converting the resitance value to temperature. The multimeter autoranges between the 200 Ω LoIΩ range and the 2 kΩ Normal Ω range depending on the resistance value obtained at the temperature being measured. Press the PRT key to show the PROBE # menu:



adj105f.eps Select OK to ensure the probe indicated is selected. Probe# Menu

Prt

adj106f.eps PRT CONFIG Menu  Provides selection for temperature units.

8508A

adj107f.eps PROBE CONFIG Menu The utilization and management of PRT probe data depends upon a probe identity. For example, before using the edit and delete capabilities a probe identity must be selected. For a new probe, defining an identity is the first step in the sequence of establishing the probe’s characteristics. New PROBE Entry

adj108f.eps PROBE# Menu For entry of the characteristics of a new PRT probe a directed sequence of menus, initiated with a NEW command, should be followed. The first menu establishes the identity of the probe using the alphanumeric keyboard entry system. (NOTE: no duplication checks are made on the identity.)

adj109f.eps Connection Menu Selection of the connection method will determine the measurement configuration that is used by the Multimeter. This characteristic cannot be modified via the Edit capability.  2-wire probe configuration. Resistance measurements will be made using the 2-wire connection, with a single polarity stimulus current.  3-wire probe configuration. An equivalent 3-wire measurement will be made by automatically taking a reading with the resistance circuits in 2- wire with a single polarity stimulus current and also in 4-wire with polarity reversal of the stimulus current, and performing a calculation. Equal resistance is assumed for all three probe-leads. Input zeros for 2-wire and 4-wire resistance must be performed prior to the selection of the PRT as these are used in the calculation to remove offsets and internal lead resistance.  4-wire probe configuration. Resistance measurements will be made using the 4-wire connection, with a polarity reversal of the stimulus current.

Making Measurements

Using the Measurement Functions 3

3-27

adj110f.eps Conversion Menu Select the conversion algorithm to be applied. This characteristic cannot be modified via the Edit capability. A measurement annunciator in the left-hand display indicates the active conversion algorithm. This algorithm converts resistance to temperature according to the ITS-90 specifications for SPRTs. For details see the NIST Technical Note 1265, Guidelines for Realizing the International Temperature Scale of 1990. The user-defined parameters for the ITS-90 conversion include two subranges which are entered in subsequent conversion specific menus.  This algorithm converts resistance to temperature using the Callender-Van Dusen equations. The user-defined parameters are supplied in the Alpha(α), Delta(δ), and Beta(β) format and are entered in subsequent conversion specific menus.  This algorithm converts resistance to temperature using the Callender-Van Dusen equations. The user-defined parameters are supplied A, B, C coefficients and are entered in subsequent conversion specific menus. Note The coefficients Alpha(α), Delta(δ), Beta(β) and A, B, C belong to reciprocally related polynomial expressions. Either may be used according to preference or available data.  This algorithm converts resistance to temperature using the Callender-Van Dusen equations. The only user-defined parameter is the R0 value entered in a subsequent conversion specific menu. The other coefficients are defaulted to A = 3.9083E-3, B = -5.775E-7, C = -4.183E-12. Coefficient Entry for a New PROBE On selection of a conversion method the algorithm specific coefficients are set to default values. The subsequent menus to modify these coefficients are conversion specific. The default value for the coefficient may be entered with a labeled softkey. 

adj111f.eps Coefficient Menus

8508A

adj131f.eps Figure 3-11. PRT Connections

Making Measurements

Multimeter Inputs 3

3-29 Multimeter Inputs Input The Input key and its menu allow you to select either the Front or Rear panel terminals as the input to the Multimeter: The scan softkey gives access to dual-channel measurement and processing selection which produces a single result. Using the INPUT Key Press the Input key to see the INPUT menu:

adj113f.eps INPUT key Menu  Selects Front Input terminals only.  Select Rear Input terminals only. Note Total Isolation State -You can put the Multimeter in a state of total isolation by deselecting all the selections on the INPUT and SCAN menus. In this state, the Multimeter has no input. This state is useful in a remote control system, to isolate the Multimeter from the system’s analog bus.  Readings are taken alternately from each channel, then measurements are combined as per the selection. Note Selecting Front or Rear cancels any Scan selection.  When On, the internal guards are decoupled from Lo and connected to the Guard terminal. Operation of Guard in the resistance function is modified, and includes Ohms Guard. Refer to the ‘making measurements’ section for each function for more details.  Initiates a series of measurements to determine and correct for the Input Zero and save the result in volatile memory. An indication of the application of an input zero will appear on the left-hand display. Independent zero corrections are provided for Front and Rear terminals and, when in Ohms functions, 2 wire and four wire connections and normal and low current operation. Input Zero may be up to 0.5 % of Range. For AC always use the lowest possible range. After the Input Zero all subsequent readings will be RSS corrected by this zero.  Initiates a series of measurements on each range in the function starting with the highest range, to determine and correct for the Input Zero for each range. Note Input Zeros - Input zero stores are cleared on power up, and may also be cleared by the user from the CLEAR menu, accessed by pressing the CLEAR key.

8508A

Scan Operations

adj128f.eps Scan Menu In each of three Scan modes, measurements are taken alternately from the Front and Rear Terminals and are combined mathematically to produce a single result as shown below.  Readings are taken alternately from the front terminals and then the rear to produce the displayed result; Front reading – Rear reading.  Readings are taken alternately from the front terminals and then the rear to produce the displayed result; Front reading / Rear reading.  Readings are taken alternately from the front terminals and then the rear to produce the displayed result; This is the normalized ‘deviation’ value. Note Scan of the Current functions - Scan is not available in the ACI and DCI functions. Note Scan of the Ohms functions - In the Ohms and HiV Ohms functions the Scan Operation switches both current stimulus and potential difference measurement between the Front and Rear terminals. The Tru Ohms Ratio feature described below scans only the potential difference measurement between Front and Rear terminals, maintaining stimulus current through both Front and Rear terminals.  Warning

Danger Of Lethal Electric Shock

Making Measurements

Multimeter Inputs 3

3-31 Caution

High Voltage

Input Lo

Sense Lo

Sense Hi

Input Hi

Input Lo

Sense Lo

Sense Hi

Input Hi

adj132f.eps Figure 3-12. TruΩ Ratio Measurements The sequence of measurement is:

8508A

adj116f.eps MONITOR menu Displaying Signal Frequency When measuring AC voltage or current, select the Freq key to display the frequency corresponding to the rms value shown on the main display. The response rate for the ACV function frequency measurements can be set in the MONITOR CONFIG menu. When Fast is not selected, the frequency measurements are made with a 1 s response rate at a 6.5- digit resolution, otherwise all frequency measurements are made with a 50 ms response rate at a 4.5-digit resolution. The 1 s response rate will slow down the ACV reading rate. Displaying Standard Deviation Press the Devn key to calculate and display the population standard deviation of a block of readings.

The population standard deviation is calculated as ( ) x x n n − −  2 1 1

For the standard deviation of a rolling block of readings the AvR rolling average mode must be configured and selected from the MATH menus.

For the standard deviation of a fixed block of readings the BlocN block average mode must be configured and selected from the MATH menus.

Devn Menu

adj146f.eps Standard Deviation Menu This menu allows selection of the displayed format for the standard deviation.  Displays the standard deviation of the block relative to the block mean.  Displays the standard deviation of the block as an absolute value.  

adj147f.eps Standard Deviation display

Making Measurements

Monitoring Modes 3

3-33 Displaying Maximum, Minimum, and Peak-to-Peak Readings The MAX, MIN, and PKPK menus have the same format and show information derived from measurements taken since the Min, Max, or Pkpk mode was reset. Once one of the three menus has been entered, you can select either of the other two without going through the MONITOR menu. MAX or MIN can be cleared by its own Reset soft key, but the Reset soft-key on the PKPK menu clears both the Max and Min memory. In DCV and DCI, the MAX value is the most positive (or least negative) measurement and the MIN value is the most negative (or least positive) measurement. Note Because Pkpk does not store a value except as a result of calculating the difference between a maximum and a minimum value, if the MAX or MIN memory is cleared, the PKPK menu value is also cleared until the first measurement enters the cleared memory. After this, the PKPK menu value reflects the change by showing the new difference between the maximum and minimum values. The Multimeter does not clear the MAX or MIN values upon a change of function, range, or other measurement parameter. These can be cleared only by pressing the appropriate Reset key. MAX Menu

adj117f.eps MAX menu Limit-Checking Select the Limit key to display whether high and low limits that were previously set, have been exceeded by the most recent measurement. The display indicates a HI LIMIT if the most recent measurement is above the high limit of a preset range, LO LIMIT if it is below the low limit, or PASS if it is within the limit range. Limits can de defined from the LIMIT menu, or from MONITOR CONFIG Menu.

adj118f.eps LIMIT menu The last HI LIMIT/ LO LIMIT value is displayed and the numeric keyboard is activated to allow entry of a new limit. Enter completes the new limit or Quit leaves the value unchanged.

8508A

On/Off

adj114f.eps Monitor Menu Tree Note From any of these menus, pressing the Config hard key will enter the MONITOR CONFIG menu; pressing the Monitor key reverts to the MONITOR menu. Utility Press the Utility key to see the UTILITY menu:

adj119f.eps Utility Menu This menu has the following menu key selections: Displays the ADDRESS menu to view and change the IEEE-488 bus address of the Multimeter.   Provides a contrast menu for adjustment to the left hand or main display.

Making Measurements

Utility 3

3-35   Provides a contrast menu for adjustment to the right hand display.  Provides selection of the power line frequency for the Multimeter.  When in ACV function this softkey displays the SPOTF menu to view the spot frequencies at which the Multimeter has been calibrated.  Displays the SER# menu, to view the serial number of the Multimeter and version of the software in it.  Displays the CAL DUE date. This shows the user-entered recommended date for recalibration of the instrument.   Provides selection for display styles for the measurements.

Ieee 488 Address

adj120f.eps IEEE Bus address key Menu The menu displays the present address value, and the numeric-keyboard keys are activated. Any valid numeric value (0-30) may be entered. LINE Frequency

adj121f.eps Line Frequency This selection adjusts the integration time of the Analogue to Digital convertor to align with an integral number of power line cycles at 50 Hz or 60 Hz. Correct setting is critical to the Normal Mode and Common Mode rejection of the instrument. Once set, the LINE frequency is retained even after the Multimeter is turned OFF. SPOTF Menu

adj122f.eps SPOTF Menu This display is for information only. The Spot Frequencies cannot be altered except via Calibration at new values. The SPOTF menu has six soft keys (Sp1 through Sp6), each allows the user to view one of the six possible spot frequencies that could have been calibrated for the currently active ACV range.

8508A

adj123f.eps Ser# display This display is for information only. The serial number cannot be altered except in one of the calibration menus at the factory. The software issue number (last four digits) is embedded in the software itself, and is not user-alterable.

adj144f.eps DP Style Menu The DP style allows the selection of the display format for the readings.

Usa

Eur

Uk

adj387f.eps

adj145f.eps Calibration Due Menu Calibration Due: this displays the date optionally entered during the exit from the most recent calibration.

Making Measurements

Using the Selftest Functions 3

3-37 Status Reporting - Movement between Menus

adj124.eps Status Reporting -- Movement Between Menus Using the Selftest Functions This section covers the Multimeter's selftest functions that can be performed via the Test key. An overview of the Test mode and a diagram of the Test menu tree is provided in the following figure.

8508A

adj125.eps Test Menu Tree

Making Measurements

Using the Selftest Functions 3

3-39 Test Key Press the Test key to display the TEST menu, from which you can choose to perform a variety of selftests.

adj126f.eps TEST Menu The TEST menu allows you to initiate front panel display and key tests and ‘Circuit’ test. Please note that the instrument should be allowed a warm up period of 10 minutes before performing an internal self test and that ambient temperature should be between 15 oC and 35 oC.  Press any key other than Test to step both displays through a sequence of 'walking strobes', which allow you to inspect segments and complete blocks. Press Test during the Disp checks to terminate the display test.  Press Keys to test all keys other than Test. The key's hexadecimal matrix position appears to the left of a colon; to the right of the colon an S is followed by the key's switch number, and the name of the key is given on the right of the display. Press Test during the Key checks to terminate the key test.  Press to start a selftest and disable all other function keys, signal inputs and normal trigger sources. While selftest is running the display shows a reference number of the test currently being performed. A fail indicator (?) may be added to the display, and this will persist to the end of the test sequence. Press the Abort key to stop the test. In the TEST ABORT and TEST UNSUCCESSFUL menus, repeatedly pressing the List key reads out the failures in turn. The memory of each failure is lost as it is read. Appendix A contains a list of the failure-message numbers. Note The success of Selftest can be inhibited by: Temperature not in the range: 5 °C to 40 °C, and presence of excessive RFI or Line noise.

8508A

adj127f.eps Math Menu Tree Press the Math key to display the MATH menu. The MATH menu provides selections for a variety of linear, averaging, and logarithmic calculations.

adj129f.eps MATH Menu Mathematical operations are performed on the readings obtained from the main measurement function in strict left-to-right order. All operations are independently selectable. The activation of any math operation displays the ‘MATH ’ legend on the main (left-hand) display and the measurement units e.g.V will not be displayed except when the only math operation is ‘–C’. An exponent is added to the numeric value displayed to scale the mathematical results. All constants (except %) used in the mathematical operations are set in the MATH CONFIG menu.

Making Measurements

Using the Math Functions 3

3-41 Note From any of the menus below, pressing the Config key enters the MATH CONFIG menu; pressing the Math key reverts to the MATH menu. Press Enter or Quit to revert automatically to the MATH CONFIG menu.  Causes a rolling average of R readings to be made. AvR cross-cancels with BlocN.  Causes a block average of N readings to be made. BlocN cross-cancels with AvR.  Causes the measurement to be multiplied by a constant, m. − Causes a constant, c, to be subtracted from the measurement.  Causes the measurement to be divided by the constant, z.  Causes the measurement to be expressed in dB relative to 1, or to z, or to dBref. Constants dBref and z are defined via the MATH CONFIG menu.  Causes the measurement to be multiplied by 100. Math Configuration Press the Config key from the MATH menu to display the MATH CONFIG menu, from which you can store the various constants used by the Math operations.

adj130f.eps MATH CONFIG menu The MATH CONFIG menu has six menu keys.  Provides selection of the number of readings used in rolling average.  Provides a numeric entry menu for the value of N. The most recent N value is shown and the keyboard is activated. Press Enter to store the new value or Quit to leave the old value intact and return to the MATH CONFIG menu.  Provides a numeric entry menu for the value of the multiplier constant, m.  Provides a numeric entry menu for the value of the subtractor constant, c.  Provides a numeric entry menu for the value of the divisor constant, z.  Provides selection of the decibel reference constant, dBREF. Only voltage functions can utilize all the settings. Other functions will utilize a unity reference.

50 Ω

75 Ω

8508A

adj143f.eps CLEAR Menu The ‘input zero’ corrections will remain active until power down, but the selections available in this menu will allow the corrections to be cleared.  Removes the correction for the currently selected range and function.  Removes the correction for all ranges for the currently selected function.  Sets the instrument to the conditions which exist at power up.

4-1 Chapter 4 Remote Operations Using the IEEE 488 Interface

Title Page Introduction .......................................................................................................... 4-3 Interface Capability: IEEE Standards 488.1 and 488.2 ....................................... 4-3 The Multimeter in IEEE 488.2 Terminology .................................................. 4-3 Programming Options ..................................................................................... 4-3 Capability Codes ............................................................................................. 4-3 Interconnections ................................................................................................... 4-4 Using the 8508A Reference Multimeter in a System .......................................... 4-5 Setting the Multimeter Address ....................................................................... 4-5 Remote Operation General Considerations ..................................................... 4-5 Syntax Diagrams in this Manual ..................................................................... 4-5 The 8508A Status Reporting Structure ............................................................ 4-8 Types of Status Information Available ............................................................ 4-9 Syntax Diagrams of Major 8508A Functions ...................................................... 4-10 DC Voltage ...................................................................................................... 4-10 AC Voltage ...................................................................................................... 4-11 Resistance: Normal OHMS ............................................................................. 4-13 Resistance: High Voltage OHMS .................................................................... 4-14 Resistance: True OHMS .................................................................................. 4-15 DC Current ...................................................................................................... 4-16 AC Current ...................................................................................................... 4-17 Using Platinum Resistance Thermometers to obtain Temperature. ................ 4-18 Determine the PRT identity. ............................................................................ 4-18 Entering or Editing the Characteristics of a PRT to Non-volatile Store ......... 4-19 Recalling the Characteristics of a Known PRT ............................................... 4-20 Deleting a Known PRT from the Non-volatile Store ...................................... 4-20 Input ................................................................................................................. 4-21 Guard ............................................................................................................... 4-21 Measurement Gate Width ................................................................................ 4-22 Maximum, Minimum and Peak-Peak .............................................................. 4-22 Limits ............................................................................................................... 4-24 Recall Limits ................................................................................................... 4-24 Enable Limits ................................................................................................... 4-24 Standard Deviation .......................................................................................... 4-25 Syntax Diagrams of Math Functions ................................................................... 4-25 Averaging ........................................................................................................ 4-25 Multiplication .................................................................................................. 4-27

8508A

Remote Operations Using the IEEE 488 Interface

Introduction 4

4-3 Introduction Chapter 4 provides the information necessary to operate the 8508A Reference Multimeter remotely via the IEEE 488 Interface. (Hereafter, the 8508A is also referred to as "the Multimeter" or, in the context of IEEE 488.2 terminology, "the device") For users unfamiliar with the IEEE 488 Interface, refer to the standard specification, which appears in the publications ANSI/IEEE Std. 488.1-1987 and IEEE Std. 488.2-

8508A

Ieee 488.1

Interface Function

Sh1

Ah1

T6

L4

Sr1

Rl1

Pp0

Dc1

Dt1

C0

E2

adj194f.eps IEEE 488 Input/Output - Pin Layout and Designations Pin No. Name Description 1

Dio 1

Dio 2

Dio 3

Dio 4

Eoi

Dav

Nrfd

Ndac

Ifc

Srq

Atn

Shield

Dio 5

Dio 6

Dio 7

Dio 8

Ren

Gnd 6

Gnd 7

Gnd 8

Gnd 9

Gnd 10

Gnd 11

Gnd

Figure 4-1. IEEE 488 Input/Output Connector

Remote Operations Using the IEEE 488 Interface

Using the 8508A Reference Multimeter in a System 4

4-5 Using the 8508A Reference Multimeter in a System Setting the Multimeter Address The Multimeter will only respond to Talk or Listen commands from the controller at a specified address. The Multimeter address can only be set manually; using the ADDRESS menu that is accessed via the Utility menu. To change the address, proceed as follows:

adj119f.eps UTILITY menu

adj120f.eps ADDRESS menu The menu displays the present address and the numeric-keyboard keys are activated.

8508A

adj199f.eps Syntax Diagram of a Simple Program Message Use of Italics Notice that the names of some elements are shown here in italics which indicate "non- literal" text (i.e., names given to particular elements) The actual characters to be sent, are shown in plain-text capitals. Upper/Lower Case Equivalence The Multimeter will not differentiate between upper and lower case characters in literal program text. Numeric Representation The Multimeter accepts a "Flexible Numeric Representation" (Nrf), when receiving numbers. Decimal numeric responses from the Multimeter are in either Nr1 or Nr3 format. In this manual, all syntax diagrams for query contain the response format. The Program Message Terminator The message terminator for the 8508A Reference Multimeter is the hexadecimal number 0A , characterized in IEEE 488.2 as NL. Alternatively, the EOI (end or identify) line can be set true with the last byte to be sent. This is represented on the syntax diagram by

/^End/.

adj352f.eps Non-Terminal Program Message Unit To save space, the name ‘program header separator’ is abbreviated to ‘phs’.

Remote Operations Using the IEEE 488 Interface

Using the 8508A Reference Multimeter in a System 4

4-7 Data Element , Program Header phs

adj201f.eps Program Header Separator - phs The Program Header The ‘Program Header’ provides the main command identification. This may be followed by ‘Program Data Elements’ and these must be separated from the ‘Program Header’ by a ‘Program Header Separator’. The Program Header Separator The ‘Program Header Separator’ is one or more ‘white space’ characters excluding the message terminator (NL). Program Data Elements Four versions of the defined program data elements are employed. They are emphasized in the following syntax diagrams, taken from the commands available for the Multimeter:

Trg_Srce

Int

Ext

adj203f.eps Character

Block

adj204f.eps Decimal Numeric (Nrf can be expressed in any of the ways defined by the Standard document.)

Serial

adj205f.eps String ( The maximum size of the string is specified in the command detail.) Arbitrary Block Data Elements Both the "Definite" and "Indefinite" forms specified in the Standard document are used, as shown in the Syntax diagram below. The user message must be limited to a maximum of 63 bytes. The Definite form can be fitted into an assembly of message units, but the Indefinite form (lower path) has no exit to further message units. In this case the program message must be terminated to inform the instrument that the block is complete.

8508A

∗Pud

/^End/

Nl

adj206f.eps Arbitrary Block Data Element The 8508A Status Reporting Structure The IEEE 488.2 status reporting structure provides the application programmer with a mechanism to choose the status information required at each stage in the application program. Note: The registers are binarily weighted - the numbers in the boxes are bit numbers, not weighted values. Measurement Event Status Summary Bit 0

Mss

Esb

Mav

Mes

Status Byte

Register

Pon

Urq

Cme

Opc

Exe

Dde

Qye

Rqc

O-L

Llm

Hlm

Min

Mof

Mesr?

Mese?

Rqs

Rav

∗ Sre?

∗ Stb?

∗ Ese?

∗ Esr?

Max

Stc

adj208f.eps Figure 4-2. 8508A Status Report Structure

Remote Operations Using the IEEE 488 Interface

Using the 8508A Reference Multimeter in a System 4

4-9 Standard-Defined and Device-Specific Features In the 8508A, the structure has three main registers, as follows: • The Status Byte Register, and its associated enable register, control the generation of the Status Byte, which summarizes the remainder of the status structure. • The Event Status Register, and its associated enable register, control the generation of the Event Status Byte, whose component bits report Standard-defined types of events. This register is summarized by the ESB bit 5 in the Status Byte. • The Measurement Event Status Register, and its associated enable register, control the generation of the Measurement Event Status Byte, whose component bits relate to measurement events in the 8508A. It is summarized by the MES bit 0 in the Status Byte. In the Event Status Byte the EXE bit is associated with a queue of execution errors related to the 8508A programmed condition, and the DDE bit is associated with a queue of device-dependent errors related to 8508A internal faults. A Note about Queues. These are 'historical' (Last-in - Last Out) stacks, and when the queue stack is full the eldest entries are discarded. It is recommended that the application read the queue as soon as its summary bit is set true, particularly the error bits, otherwise the original cause of the error can be discarded as subsequent dependent errors fill up the stack. However any message indicated by the MAV bit should be read before attempting to obtain the ESR status byte. Access via the Application Program The application designer has access to three enable registers to enable or disable any individual bit in these registers. Thus the application programmer can decide which assigned events will generate an SRQ, by enabling their event bits and then enabling the appropriate summary bit(s) in the Status Byte. The Controller can be programmed to read the Status Byte during a resulting serial poll, and be directed to the appropriate Event Register to discover which event was responsible for originating the SRQ. Types of Status Information Available Status Summary Information The Status Byte (STB) consists of flag bits which direct the Controller’s attention to the type of event which has occurred. Standard-defined events The following events are flagged in the 8-bit latched Event Status Register (ESR), read- accessible to the controller. • Power On - the instrument’s power supply has been switched on. • User Request - This capability is not available in the 8508A. • Command Error - a received bus command does not satisfy the syntax rules programmed into the instrument interface’s parser, and so is not recognized as a valid command. • Execution Error - a received command has been successfully parsed, but it cannot be executed owing to the current programmed condition of the instrument.

8508A

Dcv

Auto

Filt_On

Filt_Off

Resl5

Resl6

Resl7

Resl8

Fast_On

Fast_Off

Two_Wr

Four_Wr

adj209f.eps DC Voltage

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Major 8508A Functions 4

4-11 Nrf A numeric value that selects the range for the expected signal. For example, an Nrf of 2, 10, or even 15.6789, selects the 20 V range. Any valid numeric value cancels autorange.

Auto

Filt_On / Filt_Off

Resl5 / Resl6 / Resl7 / Resl8

Fast_On / Fast_Off

Two_Wr

Four_Wr

Acv

Auto

Filt100Hz

Filt40Hz

Filt10Hz

Accp

Dccp

Tfer_Off

Tfer_On

Resl6

Resl5

Filt1Hz

Spot_On

Spot_Off

Two_Wr

Four_Wr

adj210f.eps AC Voltage

8508A

Auto

Filt100Hz / Filt40Hz / Filt10Hz / Filt1Hz

Tfer_On

Tfer_Off

Dccp

Accp

Resl5 / Resl6

Spot_On / Spot_Off

Two_Wr

Four_Wr

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Major 8508A Functions 4

4-13 Recall of Spot Frequency Value

Spot?

adj211f.eps Recall of Spot Frequency (Nr3) Recalls the frequency value for the specified calibrated spot on the active ACV range. Resistance: Normal OHMS The following commands are used to select the Normal OHMS function and set its configuration.

Ohms

Auto

Filt_On

Filt_Off

Resl5

Resl6

Resl7

Resl8

Fast_On

Fast_Off

Two_Wr

Four_Wr

Loi_Off

Loi_On

adj212f.eps Normal OHMS Nrf A numeric value that selects the range for the expected signal. Any valid numeric value cancels autorange.

Auto

Filt_On / Filt_Off

8508A

Resl5 / Resl6 / Resl7 / Resl8

Fast_On / Fast_Off

Two_Wr

Four_Wr

Loi_On / Loi_Off

Hiv_Ohms

Filt_On

Filt_Off

Resl5

Resl6

Resl7

Four_Wr

Two_Wr

Fast_Off

Fast_On

Resl8

adj213f.eps High Voltage OHMS Nrf A numeric value that selects the range for the expected signal. Any valid numeric value cancels autorange.

Filt_On / Filt_Off

Resl5 / Resl6 / Resl7 / Resl8

Fast_On / Fast_Off

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Major 8508A Functions 4

4-15

Two_Wr

Four_Wr

20 Mω, Filt_Off, Resl6, Fast_Off, Two_Wr

True_Ohms

Auto

Resl5

Resl6

Resl7

Resl8

Fast_O

Loi_On

Ff

Fast_On

Loi_Off

adj214f.eps True OHMS Nrf A numeric value that selects the range for the expected signal. Any valid numeric value cancels autorange.

Auto

Resl5 / Resl6 / Resl7 / Resl8

Fast_On / Fast_Off

Loi_On / Loi_Off

8508A

Dci

Auto

Filt_On

Filt_Off

Resl5

Resl6

Resl7

Fast_Off

Fast_On

adj215f.eps DC Current Nrf A numeric value that selects the range for the expected signal. Any valid numeric value cancels autorange.

Auto

Filt_On / Filt_Off

Resl5 / Resl6 / Resl7

Fast_On / Fast_Off

2A, Filt_Off, Resl7, Fast_On

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Major 8508A Functions 4

4-17 AC Current The following commands are used to select the ACI function and set its configuration.

Aci

Auto

Filt100Hz

Filt40Hz

Filt10Hz

Filt1Hz

Dccp

Accp

Resl5

Resl6

adj216f.eps AC Current Nrf A numeric value that selects the range for the expected signal. Any valid numeric value cancels autorange.

Auto

Filt100Hz / Filt40Hz / Filt10Hz / Filt1Hz

Resl5 / Resl6

Dccp

Accp

2A, Filt40Hz, Resl6, Accp

8508A

Prt

Deg_K

Deg_C

Deg_F

Resl5

Resl6

Resl7

Resl8

adj356f.eps Platinum Resistance Thermometers Identity This is a string value and thus must be enclosed in double quotes and must be identical in all respects with the identity of an already entered PRT. This command will set the selected PRT as the active measurement probe.

Deg_K / Deg_C / Deg_F

Resl5 / Resl6 / Resl7 / Resl8

Prt?

adj353f.eps PRT Identity Response: (string) Active Probe, (string) next inactive probe There is always the one identity returned as a string, but the second identity is obtained from an incremental search of the available identities. If no other identities exist then the second string with the separating comma is not appended. This command can be used to increment through the list of PRT’s stored. The user should check for a second appearance of the inactive identity to determine when all possible identities have been viewed.

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Major 8508A Functions 4

4-19 Entering or Editing the Characteristics of a PRT to Non-volatile Store The following commands are used to construct a PRT identity and set associated parameters and coefficients.

Prt_Chr

Std_Prt

Cvd_Alpha

Cvd_Din

Cvd

Two_Wr

Three_Wr

Four_Wr

adj357f.eps Entering or editing PRT characteristics This command with its associated parameter can be used to enter characteristics of a new PRT identity to the non-volatile store. Identity This is a string value and thus must be enclosed in double , limited to 17 characters.

Std_Prt

Cvd_Alpha

Cvd_Din

Cvd

Two_Wr / Three_Wr / Four_Wr

Prt_Coef

adj358f.eps Entering or Editing PRT Coefficients This command with its associated parameter is used to enter the coefficients, or to edit the existing coefficients of a PRT with a known identity. NOTE that when editing all the parameters MUST be given in the correct order. The numbers entered are associated in the following manner: • For CVD only one number is required for the Rzero value. • For CVD_DIN the first number is the Rzero value, the second is the A coefficient, the third the B coefficient and the fourth is the C coefficient. • For CVD_ALPHA the first number is the Rzero value, the second is the α coefficient, the third the β coefficient and the fourth is the δ coefficient. • For STD_PRT the first number is the resistance of the probe at the triple point of water. The second is the a+ value (a7). The third is the b+ value (b7). The fourth is the c+ value (c7). The fifth is the a- value (a4). The sixth is the b- value (b4).

8508A

Prt_Data?

Prt_Data?

adj355f.eps Recalling PRT data Recalls the characterization data and associated coefficients for the probe identity given. Response Format: This is a variable length response consisting of comma separated elements : (string) Identity , algorithm , connection , (Nr3) Rtp or Rzero , (Nr3) coefficient1 , (Nr3) coefficient2 , (Nr3) coefficient3 , (Nr3) coefficient4 , (Nr3) coefficient5 The ‘Identity’ consists of 17 ASCII characters enclosed with quotes. The ‘algorithm’ will be one of the following: STD_PRT or CVD_ALPHA or CVD_DIN or CVD. The ‘connection’ will be one of the following: TWO_WR or THREE_WR or

Four_Wr.

Prt_Del

Prt_Del

adj354f.eps Deleting a known PRT Removes the probe from the store of probe data for the identity given.

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Major 8508A Functions 4

4-21 Input The following commands are used to select an input; or combined usage of the two inputs to calculate the Ratio, Difference and Deviation measurement modes. The selections are mutually exclusive.

Input

Front

Rear

Div_Rear

Sub_Rear

Devtn

Off

adj217f.eps Input and Ratio Configurations

Front

Rear

Off

Div_Rear

Sub_Rear

Devtn

Front

Guard

Int

Ext

adj218f.eps Remote Guard

8508A

Int / Ext

Gate

Fast_On

Fast_Off

adj220f.eps Measurement Gate Width

Fast_On

Fast_Off

Fast_On.

Max?

Min?

Pkpk?

adj221f.eps Recall Stored values

Max?

Min?

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Major 8508A Functions 4

4-23

Pkpk?

20.0000000E+36.

40.00000000E+36.

Clr

Max

Min

Pkpk

adj222f.eps Reset Max and Min Memories

Max / Min

Pkpk

8508A

Hilt

Lolt

adj223f.eps Setting Hi/Lo Limits Nrf A Decimal Numeric Data element that represents the mathematical value to be used for limit-checking. Its resolution is 8.5 significant digits; numbers in excess of this resolution will be rounded to it. The limits are stored in non volatile memory. Recall Limits Each of these queries recalls its corresponding limit value.

Hilt?

Lolt?

adj224f.eps Recall Limits

Hilt?

Lolt?

Limit

On

Off

adj225f.eps Enable Limits Note Limit calculations are performed after all math operations are complete. Thus the choice of limit values should be relevant to the result of the math operation on the measured signal. Power On and Reset Conditions

Off

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Math Functions 4

4-25 Standard Deviation Each of these queries recalls the stored standard deviations for a block of readings.

Devtn? Reading

Devtn? Absolute

adj363f.eps Recall Standard Deviation

Devtn? Reading

Devtn? Absolute

8508A

Avg

Av4

Av16

Av64

Bloc_N

Off

adj226f.eps Enable Averaging

Avg Av...

Avg Bloc_N

Avg Off

Off

N

adj227f.eps Set Block Size Nrf An integer value to be used as the number of readings to be taken and averaged in each block.. This value is saved in non volatile memory. Example: N 15 sets the number of readings to be averaged to 15. Execution Errors Execution errors will be generated when N > 10,000. Power On and Reset Conditions: No Change. The number N is saved at Power Off.

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Math Functions 4

4-27 Recall Block Size

N?

adj228f.eps Recall block Size

N?

Mul_M

On

Off

adj229f.eps Enable Multiplication Power On and Reset Conditions

Off

M

Last_Rdg

adj230f.eps Set multiplication constant Nrf A numeric value required for use in the MUL_M command. The decimal data resolution is 8.5 digits; numbers exceeding this resolution will be rounded to 8.5 digits. This value is saved in non volatile memory. Example:

M -3E+2

Last_Rdg

8508A

M?

adj231f.eps Recall Multiplication Constant

M?

Sub_C

On

Off

adj232f.eps Enable Subtraction Power On and Reset Conditions

Off.

C

Last_Rdg

adj233f.eps Set Subtraction Constant Nrf A numeric value required for use in the SUB_C processing. The decimal data resolution is 8.5 digits; numbers exceeding this resolution will be rounded to 8.5 digits. This value is saved in non volatile memory. Example: C 10E2 sets the C constant to 1000.

Last_Rdg

Remote Operations Using the IEEE 488 Interface

Syntax Diagrams of Math Functions 4

4-29 Recall Subtraction Constant

C?

adj234f.eps Recall Subtraction Constant

C?

Div_Z

On

Off

adj235f.eps Enable Division Power On and Reset Conditions

Off

Z

Last_Rdg

adj236f.eps Set Division Constant Nrf A numeric value required for use in the DIV_Z processing. The decimal data resolution is 8.5 digits; numbers exceeding this resolution will be rounded to 8.5 digits. Divide by zero will set bit 5 (MOF) of the Measurement Event Status Byte. This value is saved in non volatile memory. Example: Z -56.999 sets Z to -56.999.

Last_Rdg

8508A

Z?

adj237f.eps Recall Division Constant

Z?

Db

On

Off

adj238f.eps Enable dB Calculation

On / Off

Off.

Db_Ref

Unity

R50

R600

R75

adj239f.eps Set dB Reference

Unity

R50

R75

75 Ω

R600

600 Ω

Unity.

Remote Operations Using the IEEE 488 Interface

Syntax Diagram of Test 4

4-31 Recall dB Reference Value

Db_Ref?

adj240f.eps Recall dB Reference Value

Db_Ref?

+1.00000000E+00.

Tst?

adj241f.eps Selftest

∗Tst?

8508A

Ddq?

adj243f.eps Recall Device Errors

Ddq?

Exq?

adj268f.eps Recall Execution Error

Remote Operations Using the IEEE 488 Interface

Triggering and Reading Operations 4

4-33

Exq?

Trg_Srce

Int

Ext

adj244f.eps Trigger Source Selector

Int

Ext

Int.

8508A

Trg

adj245f.eps Execute Trigger

*Trg

X?

adj246f.eps Execute Trigger and Take Reading

X?

Delay

Dflt

adj247f.eps Setting Delay Nrf A numeric value for the required settle delay. The minimum period allowed is 0, and the maximum is 65,000 seconds. Examples: DELAY 0.001 sets a settle delay after trigger of 1ms before the reading begins DELAY DFLT sets the default delay for the selected function, range, filter etc. The programmed delay is active with TRG_SRCE EXT selected, although delays may be programmed whilst unit is in Remote with default (internal) triggers selected. They will then become active upon the selection of the external trigger. Delay Selection Resolution <0.01 s 10 µs 0.01 s to 0.1 s 100 µs 0.1 s to 1 s 1 ms 1 s to 10 s 10 ms >10 s 100 ms Execution Errors: Execution errors are generated if an attempt is made to program the delays when the instrument is not in remote control. An execution error is generated if the selected value of Nrf exceeds the limiting value. Power On and Reset Conditions

Dflt

Remote Operations Using the IEEE 488 Interface

Triggering and Reading Operations 4

4-35 Delay Default Tables The delays listed in the following tables are active unless a specific delay is programmed. Once programmed, a specific delay will be applied to all subsequent readings providing External Trigger mode is selected until either the DELAY DFLT command is received, or the instrument is returned to local control. Delays then return to their default values. Table 4-2. Delay Defaults for DCV, DCI, ACV, and ACI

Function Filter. Resolution 5 6 7 8

Dcv

Dci

Acv

Aci

1 Mω

10 Mω

100 Mω

1 Gω

10/100 Mω

1/10 Gω

8508A

Zero?

Mzero?

adj248f.eps Input Zero

Zero?

Mzero?

Wai

adj249f.eps Wait

∗Wai

Rdg?

adj250f.eps Reading Recall - Voltage, Current and Resistance Readings Voltage, Current and Resistance Readings

Rdg?

Remote Operations Using the IEEE 488 Interface

Triggering and Reading Operations 4

4-37 If no trigger has been received to generate a conversion of the input signal, then the response to this command will represent the most-recent measurement. If a trigger has already been received, this query will wait for the completion of the measurement before placing the result in the output queue. The value represents the applied signal together with any mathematical modifications selected with the Math facility. Overload is represented by a value of ±200.0000E+33 and the O-L bit set in the measurement event status register. Power On and Reset Conditions All previous results are cleared at power ON and Reset. Frequency Readings

Freq?

adj251f.eps Reading Recall - Frequency Readings

Freq?

Block

adj293f.eps Set and Arm Block Measurement Mode

Block

Block 16

adj294f.eps Block of 16 readings

8508A

Count?

adj295f.eps Recall Number of Results

Count?

Block?

adj296f.eps Recall Measurements from Internal Memory

Block?

Remote Operations Using the IEEE 488 Interface

Internal Operations Commands 4

4-39 Example:

Block? 6,11

Block 16

adj297f.eps Block of 16 Readings Execution Errors Occur when the start point number is greater than the finish point number, or when the finish point number is greater than the number of readings actually saved. An execution error will also result from either of the numbers being zero. Power On and Reset Conditions No stored readings are available. Internal Operations Commands All of the commands under this heading are common commands defined in the IEEE- 488.2 standard. Reset

Rst

adj252f.eps Reset

*Rst

8508A

*Opc

Opc

adj253f.eps Complete

Opc?

Opc?

adj254f.eps Complete? Status Reporting Most of the commands in this sub-section are standard reporting commands defined in the IEEE-488.2 standard.

Remote Operations Using the IEEE 488 Interface

Status Reporting 4

4-41 Measurement Event Status Summary Bit 0

Mss

Esb

Mav

Mes

Status Byte

Register

Pon

Urq

Cme

Opc

Exe

Dde

Qye

Rqc

O-L

Llm

Hlm

Min

Mof

Mesr?

Mese?

Rqs

Rav

∗ Sre?

∗ Stb?

∗ Ese?

∗ Esr?

Max

Stc

adj255f.eps Status Data Structure Read Service Request Register

Stb?

*Stb?

Sre

∗Sre

8508A

Sre?

*Sre?

Esr?

∗Esr?

Ese

∗Ese

Ese?

Remote Operations Using the IEEE 488 Interface

Status Reporting 4

4-43

∗Ese?

Mesr?

adj258f.eps Read Measurement Event Register

Mesr?

Mese

adj257f.eps Measurement Event Enable

Mese

Mese?

adj256f.eps Recall Measurement Event Enable

Mese?

8508A

Cls

*Cls

Psc

*Psc

Psc?

*Psc?

Idn?

I/D

∗Idn?

Remote Operations Using the IEEE 488 Interface

Instrument I/D and Setup 4

4-45 • Fourth field - Firmware level (issue.revision). Options

Opt?

*Opt?

Linef

Linef

adj281f.eps Setting Line Frequency 50 Hz or 60 Hz

Linef 50

Linef 60

Linef?

adj282f.eps Recall Line Frequency Setting

Linef?

8508A

Refer to Chapter 6 for details of the required calibration points and procedure. Enable Calibration

Enbcal

Extnl

Special

adj271f.eps Enable Calibration

Enbcal

Extnl

Special

Cal?

adj272f.eps Trigger External Calibration

Remote Operations Using the IEEE 488 Interface

Calibration Commands and Messages 4

4-47

Cal?

Selspot

Set

adj273f.eps Spot Frequency

Selspot

Ext_Due?

adj275f.eps Calibration Due Date

8508A

Ext_Due?

∗Pud

/^End/

Nl

adj277f.eps Protected User Data where: phs = Program Header Separator digit = one of the ASCII-coded numerals user message = any message up to 63 bytes maximum

*Pud

∗Pud?

adj278f.eps Recall User Data

*Pud?

adj279f.eps Response Syntax where:

digit = one of the ASCII-coded numerals

user message = the saved user message

Remote Operations Using the IEEE 488 Interface

Calibration Commands and Messages 4

4-49 Special Calibrations Perform a "Special" Calibration

Chse?

Adc

Freq

Hv_Lin

adj280f.eps Special Calibration

Chse?

Adc

Freq

Hv_Lin

8508A

Src_N500

Zero

Src_P500

Src_P1K

If special calibration is not enabled.

Remote Operations Using the IEEE 488 Interface

Calibration Commands and Messages 4

4-51 Exit from Calibration

Exitcal

Exit from Calibration adj284f.eps

Exitcal

Serial

adj290f.eps Set Instrument Serial Number

Serial

8508A

Clrmem

All

Hftrim

adj289f.eps Clear Calibration Memory

Clrmem

All

Hftrim

5-1 Chapter 5 Specifications

Title Page Specifications ..................................................................................................... 5-3 General Specifications ................................................................................... 5-3 Maximum Voltage and Current Inputs .......................................................... 5-4 DC and AC Voltage .................................................................................. 5-4 DC and AC Current ................................................................................... 5-4 Resistance and Temperature ..................................................................... 5-4 Electrical Measurement Specifications .............................................................. 5-5 DC Current .................................................................................................... 5-6 AC Voltage .................................................................................................... 5-7 AC Current .................................................................................................... 5-9 Resistance ...................................................................................................... 5-11 Temperature ................................................................................................... 5-13 Read Rate and Additional Uncertainty .......................................................... 5-14 Applying the Specifications ............................................................................... 5-15 Introduction ................................................................................................... 5-15 Absolute and Relative Specifications ............................................................ 5-15 Applying User’s Calibration Uncertainties ................................................... 5-16 Operating and Calibration Temperature Ranges ........................................... 5-16 Applying Temperature Coefficient Specifications ........................................ 5-16 Ratio Measurements ...................................................................................... 5-17 Additional Errors ........................................................................................... 5-17

8508A

Specifications

Specifications 5

5-3 Specifications General Specifications Power Voltage 115 V Setting ..................................................... 100 V to 120 V rms designed for additional voltage fluctuations ±10 %. 230 V Setting ..................................................... 200 V to 240 V rms designed for additional voltage fluctuations ±10 %. Frequency ............................................................... 50 Hz to 60 Hz designed for additional frequency variation of ±3 Hz. Consumption ........................................................... < 80 VA Power Cord ............................................................. NEMA 5-15 plug, IEC 60320-C13 receptacle, cable 3 core 18AWG to

Svt

Ul 61010-1:2004,

Measurement Isolation Guard to Safety Ground ......................................... < 3300 pF, > 10 GΩ. Lo to Guard In Remote Guard ................................................ < 2800 pF, > 10 GΩ (Not in Resistance function). In Local Guard .................................................... Lo and Guard terminals are internally shorted (in Resistance < 2800 pF, > 10 GΩ). Autorange Range Up ................................................................ 100 % of range. Range Down ........................................................... 9 % of range (18 % on 1000 V range). Remote Interface ................................................... IEEE 488.2 Warranty ................................................................ 1 Year

8508A

5-4 Maximum Voltage and Current Inputs Notes to maximum voltage and current input specifications • Maximum DC input equal to maximum rms input. Maximum peak input is rms x 1.414 • Specifications apply equally to front and rear input terminals except where noted below. • Front to rear isolation allows opposing polarity of maximum terminal voltage on each input. • Digital I/O Ground (DigGnd) is internally connected to Safety Ground (Ground). • Maximum Common Mode voltage with respect to Safety Ground is 1.7 x 105 VHz. DC and AC Voltage Maximum rms terminal voltages

Sense Hi

Hi

250 V

Sense Lo

1000 V

1000 V

Lo

250 V

1000 V

1000 V

A

1000 V

1000 V

1000 V

1000 V

Guard

1000 V

250 V

250 V

1000 V

1000 V

DigGnd

650 V

650 V

650 V

650 V

1000 V

1000 V

0 V

650 V

650 V

650 V

650 V

1000 V

1000 V

Sense Hi

Hi

250 V

Sense Lo

1000 V

1000 V

Lo

250 V

1000 V

1000 V

A

5 V

250 V

1000 V

1000 V

Guard

250 V

250 V

250 V

1000 V

1000 V

DigGnd

650 V

650 V

650 V

650 V

1000 V

1000 V

0 V

650 V

650 V

650 V

650 V

1000 V

1000 V

Guard

A

20 A

20 A

2 A

2 A

Sense Hi

Hi

250 V

Sense Lo

250 V

250 V

Lo

250 V

250 V

250 V

A

250 V

250 V

250 V

250 V

Guard

250 V

250 V

250 V

250 V

250 V

DigGnd

650 V

650 V

650 V

650 V

1000 V

1000 V

0 V

650 V

650 V

650 V

650 V

1000 V

1000 V

Specifications

Electrical Measurement Specifications 5

5-5 Electrical Measurement Specifications Note Fluke guarantees 8508A performance verification using specifications stated to 99 % confidence level. DC Voltage DC Voltage [1] [2] [3] Range Full Scale [15] Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [4] 24 hour TCal ±1 °C 90 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal

±5 °C

2 V

20 V

200 V

1000 V

2 V

20 V

200 V

1000 V

15 °C - 30 °C

5 °C - 15 °C

30 °C - 40 °C

5 °C - 40 °C

± V/°C

2 V

20 V

200 V

1000 V

Nmrr

8508A

5-6 DC Current DC Current [1] [2] [3] Range Full Scale [15] Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [4] 24 hour TCal ±1 °C 90 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±5 °C 95 % Confidence Level 200 µA 199.990 00 5.5 + 2.0 6.0 + 2.0 6.5 + 2.0 12 + 2.0 12 + 2.0 2 mA 1.999 900 0 5.5 + 2.0 6.0 + 2.0 6.5 + 2.0 12 + 2.0 12 + 2.0 20 mA 19.999 000 6.5 + 2.0 7.0 + 2.0 8.0 + 2.0 13 + 2.0 14 + 2.0 200 mA 199.990 00 28 + 4.0 30 + 4.0 33 + 4.0 36 + 4.0 48 + 4.0

2 A

20 A

2 A

20 A

15 °C - 30 °C

5 °C - 15 °C

30 °C - 40 °C

5 °C - 40 °C

± A/°C

2 A

20 A

Type ........................................................................ Multi-slope, multi-cycle A-D Converter Protection Front Input ............................................................... 20 A rms Rear Input ............................................................... 2 A rms, Rear Panel Fuse Settling Time 200 μA to 200 mA Ranges, to 10 ppm step size .... Filter Out < 50 ms, Filter In < 1 s 2 A Range to 100 ppm step size ........................................... < 1 s to 75 ppm step size ............................................. < 30 s to 30 ppm step size ............................................. < 5 minutes

20 A Range (at 10 A) to 300 ppm step size ........................................... < 1 s to 250 ppm step size ........................................... < 30 s to 100 ppm step size ........................................... < 5 minutes

Specifications

Electrical Measurement Specifications 5

5-7 AC Voltage AC Voltage [1] [2] [6] [7] [9] Range Full Scale [15] Frequency (Hz) Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [4] 24 hour TCal ±1 °C 90 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±5 °C 95% Confidence Level 200 mV 199.990 0 1 - 10 80 + 70 120 + 70 120 + 70 160 + 70 165 + 70 10 - 40 80 + 20 120 + 20 120 + 20 130 + 20 140 + 20 40 - 100 60 + 20 100 + 20 100 + 20 110 + 20 115 + 20 100 - 2 k 40 + 10 100 + 10 100 + 10 105 + 10 110 + 10 2k - 10 k 60 + 20 100 + 20 100 + 20 105 + 20 135 + 20 10k - 30 k 250 + 30 300 + 40 300 + 40 305 + 40 340 + 40 30k - 100 k 400 + 100 700 + 100 700 + 100 705 + 100 765 + 100

2 V, 20 V &

200 V

1000 V

2 V, 20 V &

200 V

1000 V

8508A

5-8 AC Voltage (Secondary Specifications)[1] [2] [9] Range Frequency (Hz) Temperature Coefficient

15 °C - 30 °C

5 °C - 15 °C

30 °C - 40 °C

2 V

20 V

200 V

1000 V

CMRR (1 kΩ unbalance) [5] ..................................... > 90 dB DC - 60 Hz Crest Factor 200 mV to 200 V ranges ........................................ 10:1 at 12 % range, 5:1 at 50 % range, 2.5:1 at full range 1000 V range ......................................................... 10:1 at 25 % range, 5:1 at full range Protection (All ranges) ........................................... 1 kV rms Input Impedance ................................................... 1 MΩ in parallel with 150 pF DC Accuracy (DC Coupled)................................... Add ±(50 ppm Reading + 50 ppm Range + 20 μV) Ratio Accuracy Range to Range ...................................................... Apply an RSS summation of Net Front Input and Rear Input Accuracy [17] Within Range ......................................................... Using the 24 hour specifications as appropriate, apply an RSS summation of specified accuracy of the Front Input signal and the specified accuracy of the Rear Input signal [17] Settling Time (to 100 ppm step size) 100 Hz filter ............................................................. < 0.5 s 40 Hz filter ............................................................... < 1.25 s 10 Hz filter ............................................................... < 5 s 1 Hz filter ................................................................. < 50 s Frequency Measurement Signal Amplitude Range ......................................... 5 % of range to limit set by maximum V.Hz Gate Mode Normal Fast Resolution ......................................................... 6.5 digits 4.5 digits Frequency Range ............................................. 10 Hz - 1 MHz 200 Hz - 1 MHz Accuracy (1 year, 13 °C - 33 °C) ..................... ± (10 ppm of Reading + 2 digits) ± 2 digits Sample Interval ................................................. 1 s 50 ms

Specifications

Electrical Measurement Specifications 5

5-9 AC Current AC Current [1] [2] [6] [9] Range Full Scale [15] Frequency (Hz) Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [4] 24 hour TCal ±1 °C 90 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±5 °C 95% Confidence Level 200 μA 199.990 0 1 - 10 200 + 100 250 + 100 250 + 100 475 + 100 500 + 100 10 - 10 k 200 + 100 250 + 100 250 + 100 475 + 100 500 + 100 10 k - 30 k 500 + 100 600 + 100 600 + 100 650 + 100 710 + 100 30 k - 100 k 0.35 % + 100 0.4 % + 100 0.4 % + 100 0.4 % + 100 0.4 % + 100 2 mA & 20 mA 1.999 900 19.9990 00 1 - 10 200 + 100 250 + 100 250 + 100 290 + 100 310+ 100 10 - 10 k 200 + 100 250 + 100 250 + 100 280 + 100 300 + 100 10 k - 30 k 500 + 100 600 + 100 600 + 100 650 + 100 710 + 100 30 k - 100 k 0.35 % + 100 0.4 % + 100 0.4 % + 100 0.4 % + 100 0.4 % + 100 200 mA 199.990 0 1 - 10 200 + 100 250 + 100 250 + 100 290 + 100 310 + 100 10 -10 k 200 + 100 250 + 100 250 + 100 250 + 100 290 + 100 10 k - 30 k 500 + 100 600 + 100 600 + 100 600 + 100 625 + 100

2 A

20 A

2 A

20 A

8508A

5-10 AC Current (Secondary Specifications) [1] [2] [6] [9] Range Frequency (Hz) Temperature Coefficient Input Impedance (Ω)

15 °C - 30 °C

5 °C - 15 °C

30 °C - 40 °C

200 mA 1 - 10 10 15

1.2 1.3 10 - 10 k 15 20

10 k - 30 k 15 20

2 A

0.3 0.4 2 k - 10 k 15 20

10 k - 30 k 20 30

20 A

0.04

Type ........................................................................ True rms, AC coupled. DC coupled gives ) dc (ac 2 2 +

Crest Factor ........................................................... 3:1 at 50 % range, 1.5:1 at full range Protection Front Input ............................................................... 20 A rms Rear Input ............................................................... 2 A rms, Rear Panel Fuse Settling Time 200 μA to 200 mA Ranges 2 A Range 20 A Range (at 10 A)

to 100 ppm of step to 100 ppm of step to 300 ppm of step 100 Hz filter ............................................................. < 0.5 s < 1 s < 1 s 40 Hz filter ............................................................... < 1.25 s < 2 s < 2 s 10 Hz filter ............................................................... < 5 s < 10 s < 10 s 1 Hz filter ................................................................. < 50 s < 50 s < 50 s

Specifications

Electrical Measurement Specifications 5

5-11 Resistance Resistance [1] [2] [3] Range Full Scale [15] Mode [10] Uncertainty Relative to Cal Stds Absolute Uncertainties ± (ppm Reading + ppm Range) [4] 24 hour TCal ±1 °C 90 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±1 °C 365 day TCal ±5 °C 95% Confidence Level

2 Ω

20 Ω

200 Ω

2 Mω

20 Mω

200 Mω

2 Gω

2 Ω

20 Ω

200 Ω

2 Mω

20 Mω

200 Mω

2 Gω

20 Mω

200 Mω

2 Gω

20 Gω

2 Ω

20 Ω

200 Ω

2 Mω

20 Mω

200 Mω

2 Gω

2 Ω

20 Ω

200 Ω

2 Mω

20 Mω

200 Mω

2 Gω

20 Mω

200 Mω

2 Gω

20 Gω

8508A

5-12 Resistance - Normal Mode (Secondary Specifications) [1] [2] [3] [10] Range Measurement Current Transfer Uncertainty 20 mins ±1 °C ± (ppm Reading + ppm Range) Temperature Coefficient

15 °C - 30 °C

5 °C - 15 °C

30 °C - 40 °C

5 °C - 40 °C

± Ω/°C

2 Ω

20 Ω

200 Ω

2 Mω

20 Mω

200 Mω

2 Gω

15 °C - 30 °C

5 °C - 15 °C

30 °C - 40 °C

5 °C - 40 °C

± Ω/°C

2 Ω

20 Ω

200 Ω

2 Mω

20 Mω

200 Mω

2 Gω

15 °C - 30 °C

5 °C - 15 °C

30 °C - 40 °C

5 °C - 40 °C

± Ω/°C

20 Mω

200 Mω

2 Gω

20 Gω

Type ........................................................................ True 4-wire with Ohms guard. 2-wire selectable. 2 Wire Adder .......................................................... ±(10 pA/Ir) x 10 6 ppm of Reading ±50 mΩ ±3 mΩ/°C, where Ir is the measurement current, where the temperature related factor is based on the temperature difference between the present operating temperature and the temperature where the instrument was last zeroed.

Max Lead Resistance ............................................ 10 Ω in any or all leads, 1 Ω on 2 Ω range Full Scale Measurement Voltage Normal Mode .......................................................... 200 mV/2 V/20 V Lo Current Mode ..................................................... 200 mV/2 V/20 V High Voltage Mode ................................................. 200 V Protection (All ranges) .......................................... 250 V rms, 360 V pk

Specifications

Electrical Measurement Specifications 5

5-13 Ratio Accuracy Range to Range ...................................................... Apply an RSS summation of Net Front Input and Rear Input Accuracy [17] Within Range .......................................................... Using the 24 hour or 20 minute Transfer Uncertainty specifications as appropriate, apply an RSS summation of specified accuracy of the Front Input signal and the specified accuracy of the Rear Input signal [17] Settling Time ......................................................... Up to 200 kΩ range generally the same as DC Voltage Filter In but depends on external connections Temperature Temperature Readout [1] [2] [3] Resistance Range Absolute Resistance Measurement Uncertainty 365 day Tcal ±1 °C [4] ±(ppm Reading + mΩ) [11] Typical Equivalent Temperature Measurement Uncertainty [12] Probe Type Nominal Temperature

(°C)

(Ω)

± (°C)

0 - 199.990 000 Ω

25 Ω Prt/Sprt

25 Ω Prt/Sprt

25 Ω Prt/Sprt

100 Ω Prt/Sprt

100 Ω Prt/Sprt

100 Ω Prt/Sprt

200 - 1999.900 00 Ω

100 Ω Prt/Sprt

0 - 199.990 000 Ω

25 Ω Prt/Sprt

25 Ω Prt/Sprt

25 Ω Prt/Sprt

100 Ω Prt/Sprt

100 Ω Prt/Sprt

100 Ω Prt/Sprt

200 - 1999.900 00 Ω

100 Ω Prt/Sprt

(Ω)

(Ω)

15 °C - 30 °C

5 °C - 15 °C

30 °C - 40 °C

0 - 199.990 000 Ω

200 - 1999.900 00 Ω

Type ....................................................................... 4-wire current reversal resistance measurement with readout of equivalent temperature. 2-wire and 3-wire selectable without current reversal. Refer to Resistance specifications for additional details. Temperature Range .............................................. -200 °C to 660 °C, readout also available in °F or K. Linearization ......................................................... ITS-90 or Callendar van Dusen. Entry and storage of coefficients and nominal resistance for up to 100 probes. Current Source ..................................................... 1 mA

8508A

5-14 Read Rate and Additional Uncertainty Read Rate and Additional Uncertainty Function Resolution Filter Frequency (Hz) Read Rate (readings/second) Additional Errors [13] ± (ppm Reading + ppm Range) Normal Fast Normal Fast

Dcv, Dci &

1/25 1/6 0 + 0 0 + 0.1 7

1/6 1/2 0 + 0.1 0 + 0.5 6

2 35 1.0 + 0.5 0 + 2.5 5

35 150 0 + 5 0 + 25

Acv & Aci

0 + 0

10 1/5

0 + 0

40 1/2

0 + 0

100 1

0 + 0

5 1 1/50

0 + 5

10 1/5

0 + 5

40 1/2

0 + 5

100 2

0 + 5

ACV Transfer Off [6]

1 1/25

200 + 20

10 1/2.5

200 + 20

40 1

200 + 20

100 4

200 + 20

PRT & Tru Ohms [14] 8

7

6

5

Notes to Performance Specifications [1] Specifications apply for max resolution in each function, normal mode [2] Assumes 4 hour warm-up period [3] Input zero or offset null required whenever the temperature moves more than ±1 °C from the temperature at which the previous null/zero was performed. [4] TCal = Ambient calibration temperature [5] Integration time >1 Power Line cycle [6] Valid for signals >1 % Full Scale, Transfer Mode On. Signals must be DC coupled <40 Hz. [7] Max Volt.Hertz 3 x 107 [8] >300 V, <10 kHz add: ±0.0004 x (Reading-300)2 ppm >300 V, 10 kHz - 30 kHz add: ± (0.0004 + (Frequency - 10000) x10-7) x (Reading-300)2 ppm >300 V, >30 kHz add: ±0.0024 x (Reading-300)2 ppm [9] Typical below 10 Hz for ACV, below 10 Hz and above 10 kHz for ACI. [10] Tru Ohms mode available on 2 Ω to 20 kΩ ranges. Read Rate reduced in Tru Ohms Mode. Specification for Tru Ohms same as corresponding Normal or Lo Current range [11] Valid for 4-wire sensor [12] Not including sensor uncertainty [13] Assume Range and Full Scale = 2000 V when calculating for 1000 V Range. For DCI, additional errors only apply in 5 digit resolution [14] Fast mode not available in PRT [15] The maximum display value for the Analog to Digital converter is 199 990 000 counts. This sets the maximum value measurable on each range to be a one followed by four nines. For example, the maximum measured values on the 2 V range on DC Voltage are ±1.999 900 00 V. However, the 1000 V ranges are limited to a maximum 1050 V. [16] The zero TC specification only needs to be applied if an input zero has not been performed within ±1 ºC of the current operating temperature. [17] RSS (Root Sum Square). For more information refer to the Ratio Measurements portion of the “Applying the Specifications” area of these specifications [18] >2 GΩ Relative Humidity Operating <80 % to 30°C <70 % to 40°C

Specifications

Applying the Specifications 5

5-15 Applying the Specifications Introduction The Fluke 8508A has been designed specifically for metrologists. Not only does it provide the performance metrologists need, but it is specified in a way to allow users to really understand the uncertainties of the measurements, and easily make allowance for those uncertainty contributions when performing measurement uncertainty analyses and compiling uncertainty budgets. Contemporary metrology practices, including ISO17025 based laboratory accreditation schemes, require uncertainty analysis to be performed in accordance with the statistically based techniques described in the ISO Guide to the Expression of Uncertainty in Measurement (often referred to as the ‘GUM’). For convenience, the 8508A specifications are quoted at a coverage factor of k=2, equivalent to a confidence level of approximately 95 %, as required by these methods. Specifications are also provided at a confidence level of 99 %. Performance specifications for the 8508A consist of two elements, the first is a contribution expressed as parts-per-million of the Reading, and the second contribution is expressed as parts-per-million of the Range. These must be evaluated and combined for the relevant reading and range values applicable to the measurement being made, ensuring that both elements are evaluated on the same basis, such as parts per million of the measured value or in absolute terms (volts, amps, ohms, etc). The two elements are combined by adding algebraically. For example measuring 10 V on the 20 VDC range and applying the 365 day ±1 °C specifications: First, expressing the contributions in terms of parts-per-million of the measured value: ( )

V

10 of ppm 4.3 4.0 0.3 10 20 x 2.0 0.3 ± = + ± =       + ± =

Second, expressing the contributions in volts: ( ) μV 34 10 x 4.3 20 x 10 x 2.0 10 x 10 x 0.3 5 6 6 ± = ± = + ± = − − −

The 8508A is designed to provide accuracy and stability without the need for internal auto or self calibration routines which may otherwise compromise the continuity and traceability of measurement performance history. To realise the full potential of the 8508A performance accepted metrology practices should be employed, such as performing a zeroing or null operation to remove any offsets present in the measurement setup when making DC measurements. The 8508A specifications assume that these methods are employed. Absolute and Relative Specifications The Relative to Calibration Standards specifications describe the performance of the 8508A itself for the time periods and temperature range listed excluding the uncertainty of the standards used to perform calibration of the 8508A during manufacture. The Absolute specifications include the uncertainty of the standards used to perform calibration of the 8508A at manufacture and may be used to determine the uncertainty of measurements made with the 8508A for periods up to 1 year and over a temperature range of ±5 °C from calibration. If the user has their 8508A calibrated with different uncertainties, the Relative specifications can be combined with the uncertainties applicable to that calibration to determine the effective absolute uncertainty following that calibration.

8508A

5-16 Applying User’s Calibration Uncertainties When the 8508A is calibrated by another laboratory the uncertainties of the calibration standards used may be applied by combining those uncertainties with the 8508A’s Relative to Standards specifications. The applicable calibration uncertainties and the 8508A relative specifications must both be expressed at the same confidence level, and be combined in a RSS (Root Sum Square) summation. Accepted metrology practice mandates that calibration uncertainties are stated at 95 %. Check the applicable calibration uncertainties are stated at 95 % and then combine them with the 8508A 95 % Relative specifications. For example, if the 8508A is calibrated at 10 V DC with an uncertainty of 1.5 ppm at 95 %: The absolute uncertainty at 10 V for a period of 90 days and ±1 °C from calibration is:

V

10 of ppm 3.2 10 20 2.0 4.1 5.1 2 2 ± =       × + + ± =

Operating and Calibration Temperature Ranges As a metrology tool, the 8508A will commonly be used in a calibration laboratory where the temperature would be controlled to ±1 °C, and the 8508A ±1 °C specifications are applicable to those situations. The majority of electrical calibration laboratories operate at a nominal temperature of 23 °C, the temperature at which the 8508A is calibrated by Fluke during manufacture and service. The 8508A is also capable of being calibrated at any temperature between 20 °C and 25 °C and the ±1 °C specifications will apply to operation within ±1 °C of that calibration temperature. In the 8508A specification tables the temperature of calibration is referred to as TCal. Specifications for ±5 °C are provided for situations where the 8508A is operated in environments with wider temperature variations up to ±5 °C. For applications where the knowledge of the effect of temperature on 8508A performance is important, temperature coefficients are listed in the 8508A specifications. If the operating temperature is within the range 15 °C to 30 °C the 15 °C to 30 °C temperature coefficient specifications are applicable otherwise use the 5 °C to 15 °C/30 °C to 40 °C figures, provided the temperature lies within that range. The 8508A may be operated at temperatures between 0 °C and 50 °C, but performance is not specified outside the range 5 °C to 40 °C. Applying Temperature Coefficient Specifications The 8508A specification tables include information for the typical operating conditions of ±1 °C for calibration laboratories with tight temperature control, and ±5 °C for calibration laboratories with looser temperature control or uncontrolled environments within that temperature range. For the majority of applications choosing the Absolute specifications for the most appropriate operating temperature range will be adequate. However performance at other temperatures may be determined by including an allowance for temperature coefficient over the additional temperature range. Care should be taken when making this calculation as an amount of temperature coefficient is already included in the 8508A specifications and those specifications are themselves based on combining contributions using techniques similar to those employed in uncertainty analysis. For example, consider operating at 33 °C, 10 °C from the 23 °C calibration temperature. The ±5 °C specifications already include a contribution for 5 °C of temperature difference, so this amount of temperature effect must be removed before the effect of the 10 °C difference is added. Consider 10 V on the 20 VDC range: 365 day absolute specification (95 %) at 33 °C expressed in parts-per-million of 10 V is: ( ) ( )

V

10 of ppm 16 .6 5.0 x 10 3.0 x 5 10 20 2.0 5.3 2 2 2 ± = + −       × + ± =

Specifications

Applying the Specifications 5

5-17 Ratio Measurements The 8508A Ratio mode will automatically take measurements of inputs applied to the front and rear terminals and display the result as a ratio in the voltage and resistance functions. The measurements can be made on the same range or different ranges. When making measurements on different ranges the error in each measurement is evaluated by applying the relevant specification for each range and combining the two specifications in an RSS summation, expressing the contributions in parts-per-million of the measured values. For example, making measurements of the ratio of 100 mV on the 200m VDC range and 100 V on the 200 VDC range, applying the 365 day ±1 °C Absolute specifications: ratio the of ppm 37 .7 100 200 x 2.0 5.4 10 x 100 10 x 200 x 5.0 5.4 2 2 3 3 ± =       + +       + ± = − −

Making measurements on the same range will eliminate range to range errors, such as drift since the time of calibration, and improve the result. When making measurements on the same range these errors will affect both measurements and effectively cancel, leaving short term noise and linearity as the dominant errors. The 20 minute Transfer Uncertainty Specifications are provided to describe the performance obtained when making ratio measurements on the same range. The error in each measurement is evaluated by applying the relevant 20 minute Transfer Uncertainty Specification for each value and combining the two specifications in an RSS summation, expressing the contributions in parts-per-million of the measured values. If the measurements are made within the same range, but independently (not using the ratio mode) with an elapsed time greater than 20 minutes but less than 24 hours between the measurements, then the 24 hour specifications should be applied instead. For example, making measurements of the ratio of 5 V and 10 V on the 20 VDC range, applying the 20 minute Transfer Uncertainty specifications: ratio the of ppm 61 .0 10 20 x 1.0 12 .0 5 20 x 1.0 12 .0 2 2 ± =       + +       + ± =

Additional Errors The 8508A specifications are listed for the maximum resolution in each function, using the Normal reading mode. For measurements taken in other resolutions or the Fast read mode additional error contributions listed in the Read Rate and Additional Uncertainty table must be included. These additional contributions must be added algebraically to the relevant specifications. For example measuring 10 V on the 20 VDC range at 5 digit resolution in Fast mode and applying the 365 day ±1 °C Absolute specifications: ( ) ( ) ( )

V

10 of ppm

Other additional contributions apply in certain situations and are also to be added algebraically to the relevant specifications. These additional contributions include the DC Accuracy specification to be applied when making DC measurements on the AC Voltage function when DC coupled, and the High Voltage adder when making measurements above 300 V on the AC Voltage function.

8508A

5-18

6-1 Chapter 6 Adjustment and Verification

Title Page Introduction .......................................................................................................... 6-3 Adjustment Overview .......................................................................................... 6-3 Adjustment Interval and Performance ................................................................. 6-3 Adjustment Points ................................................................................................ 6-3 Non-Nominal Values ....................................................................................... 6-4 Enabling Access to Calibration Adjustment Mode .............................................. 6-4 Calibration Menus ................................................................................................ 6-4 Accessing the Calibration Menus and Calibration Mode ................................ 6-4 Calibration Menu ............................................................................................. 6-5 SET VALUE Menu ......................................................................................... 6-5 SPOT CAL Menu ............................................................................................ 6-6 SPOT (1 to 6) RMS Menus ............................................................................. 6-6 SPOT FREQUENCY (1 to 6) Menu ............................................................... 6-7 Special Calibration .......................................................................................... 6-7 SPCL Menu ..................................................................................................... 6-7 SER # Menu .................................................................................................... 6-8 Hvlin Menu ...................................................................................................... 6-8 Non-volatile input offset compensation ............................................................... 6-9 Routine Adjustment ............................................................................................. 6-9 Equipment Required for Adjustment ............................................................... 6-10 Preparing for Adjustment ................................................................................ 6-11 Interconnections .............................................................................................. 6-12 ADC Adjustment ............................................................................................. 6-14 DC Voltage Adjustment .................................................................................. 6-14 AC Voltage Adjustment .................................................................................. 6-17 Resistance Adjustment .................................................................................... 6-19 AC Current Adjustment ................................................................................... 6-30 Frequency Adjustment ..................................................................................... 6-32 Cal Due Date Entry ......................................................................................... 6-32 Non-Volatile Input Offset Adjustment ............................................................ 6-33 ACV Spot Frequency Adjustment ....................................................................... 6-34 Performance Verification ..................................................................................... 6-35 Equipment Requirements ................................................................................ 6-36 Interconnections .............................................................................................. 6-36 Applicable Verification Tolerance and Conditions ......................................... 6-36 Preparation ....................................................................................................... 6-37

8508A

Adjustment and Verification

Introduction 6

6-3 Introduction Chapter 6 describes the calibration menus, and lists the adjustment and performance verification procedures for the 8508A Reference Multimeter. Remote commands for adjustment of the 8508A are described in Chapter 4 Remote Operations using the IEEE 488 Interface. In this chapter menu and button selections are shown as all-caps text. Adjustment Overview The 8508A is adjusted via an electronic autocal feature which allows full adjustment of all functions from the front panel (or remotely via the IEEE 488.2 Interface). No hardware adjustments are required. For each combination of function and range, an appropriate calibration standard (source) is input. At each setting, one keystroke immediately calibrates to the standard by updating an internal non-volatile memory. The instrument automatically determines whether the operation is to be a Zero or Range Gain adjustment; or for AC ranges whether it is to be a Zero, LF Gain or HF Gain adjustment. As part of the adjustment procedure, a non-volatile input-offset compensation is derived independently for the front and rear inputs. The autocal process can operate only when the rear panel Calibration switch is in the ‘Enable’ position. Applying a calibration integrity seal to prevent access to the rear panel Calibration switch is a convenient way to ensure the security of adjustment. When an adjustment operation is performed the 8508A internal adjustment memory is immediately updated. It is possible to adjust a single range or single point if the user chooses to do so. However, it is recommended that the adjustment procedure listed later in this chapter be followed closely. Adjustment Interval and Performance It is recommended that the 8508A be adjusted on either a 365-day or 90-day interval depending on the requirements of the applications for which the 8508A is used and the performance specifications required. The performance of the 8508A is specified for periods of 365 days and 90 days – if readjustment takes place on a 90-day cycle use the 90-day specifications for improved performance. During manufacture, the 8508A is adjusted with low uncertainties, reflected in the Absolute Specifications listed in Chapter 5 Specification section. After readjustment, the user should apply the uncertainties for the standards and for the process applicable to that adjustment by combining those calibration uncertainties with the 8508A Relative to Standards specifications, as described in Chapter 5. Many 8508A owners prefer using Fluke calibration services instead of maintaining their own standards to support their 8508A.To help ensure optimum performance from the 8508A, Fluke offers our calibration service at a variety of worldwide locations. Our worldwide service network provides fast efficient calibration to ensure low uncertainties and optimum accuracy consistent with the original adjustment at manufacture. Adjustment Points There is generally more than one adjustment point for each range. An initial measurement (made when the adjustment is triggered) determines the intended adjustment point. The points for each range and function are listed later in this chapter.

8508A

Adjustment and Verification

Calibration Menus 6

6-5 Calibration Menu This menu allows adjustment operations at the adjustment point nominal values via Auto, or selection of adjustment operations at non-nominal values via Set. It also offers access to the special calibration menu. The CAL legend appears in the left-hand display when in CAL mode.

adj134f.eps CALIBRATION Menu This menu defines four menu keys:  Indicates to the user that the adjustment point is automatically set according to the amplitude (and frequency in ACV) of the signal detected. Auto is the default selection on entry to the CALIBRATION menu. Refer to the tables appearing later in this chapter for the adjustment points for the selected range.  The Set feature is available in all functions, allowing the user to enter the true value of the calibration standard where it differs from the nominal adjustment point value. Pressing Set displays the SET VALUE menu except in ACV Spot Frequency mode, when the SPOT CAL menu is displayed. Spot Frequency adjustment reduces flatness errors within ± 10 % of the spot frequency. Set is not available for DCV, DCI, and Resistance range zero calibrations.  Special CAL is indicated on the main display. The SPCL menu is displayed which allows pre-adjustment of the instrument, adjustment of the frequency counter, and entry to other calibration utilities.  Exits from the CALIBRATION menu via the CALIBRATION DUE ? menu, where the recommended next adjustment date can be entered, before finally quitting the calibration mode. SET VALUE Menu This menu is obtained by pressing the Set key in the CALIBRATION menu on all functions except ACV Spot Frequency.

adj139f.eps SET VALUE Menu When this menu appears, it shows the nominal adjustment point value, allowing the user to enter the true output value of the calibration standard at the point to be adjusted. The numeric keyboard is activated, locking out all other keys. The Set value is entered in exponential format expressed in Volts, Amps, or Ohms, and must be above 20 % of range (40 % on the 1000 V DCV and ACV ranges). The SAMPLE key has no effect until the Set value is stored by pressing the Enter key. The 8508A always chooses the most-recently stored Set value when adjusting. Set is not available for DCV, DCI, and Resistance range zero adjustments.

8508A

adj140f.eps SPOT CAL Menu This menu allows a user to select a spot frequency (Spx) for the selected range. It defines six menu keys: : Displays the SPOT 1 RMS menu, where users define the RMS value for the Spot Frequency 1 adjustment point on the currently selected range. : Same as Sp1 but permitting their own RMS values to be defined. SPOT (1 to 6) RMS Menus On entry to one of the six SPOT (x = 1 to 6) RMS menus, the nominal cardinal point value is displayed and the numeric keyboard is activated. A numeric value can be entered that represents the RMS value of the calibration standard signal.

adj141f.eps SPOT n RMS Menus  Stores the displayed RMS value and de-activates the numeric keyboard.

The dot-matrix display moves to the SPOT FREQUENCY (1 to 6) menu, showing the adjustment signal frequency.  Reverts to the SPOT CAL menu, not storing any new Spot value. Note The SAMPLE key is still enabled in the next menu.

Adjustment and Verification

Calibration Menus 6

6-7 SPOT FREQUENCY (1 to 6) Menu Enter this menu by pressing Enter in the SPOT (1 to 6) RMS menu, which also stores the RMS value keyed in during this menu. The value in the SPOT FREQUENCY (1 to 6) menu is the measured frequency of the present adjustment input signal.

adj142f.eps SPOT FREQUENCY n Menu Pressing the SAMPLE key causes the selected ACV range to be spot-adjusted at the adjustment signal frequency. The frequency value is stored and can be viewed from the UTILITY menu. If ACV Spot Frequency mode is selected, any subsequent measurement on this range whose frequency is within ±10 % of the stored frequency is accuracy enhanced by reducing frequency response flatness errors. Adjust the spot at a new frequency: To adjust the spot at a new frequency, change the input signal to the desired new frequency and press SAMPLE as before.  Reverts to the SPOT CAL menu with the original Spot adjustment intact. Special Calibration The SPCL menu provides alignment of the ADC and adjustment of the frequency counter. It also allows the High Voltage Linearity Pre-Adjustment to be performed and a section of the Non-Volatile memory to be cleared for test purposes. These facilities are used in the factory for initial pre-adjustment processes; they should not require access during the life of the instrument unless repairs have been carried out. They appear here for completeness. SPCL Menu The SPCL menu appears after pressing the Special key in the CALIBRATION menu. At the same time the instrument is placed in special calibration mode, the Special CAL legend appears on the main display. When in Special CAL mode the following front panel keys remain inoperative: CLEAR, TEST, OFFSET, PRT and INPUT. Also, the function of the SAMPLE key changes to become the trigger key for initiating the Hvlin adjustment operation.

adj137f.eps SPCL Menu The SPCL menu provides the selection:  Aligns the different resolutions available from the instrument's analog-to- digital converter, so that there are no significant differences in readings when changing resolutions with a constant input value. No external input signals are required for this adjustment. Adjustment is initiated directly by making this selection from the SPCL menu.  Calibrates the frequency counter against an external source. Adjustment is initiated directly by making this selection from the SPCL menu.

8508A

adj138f.eps SER# Menu The SER# menu provides the selection:  Stores the new serial number, de-activates the numeric keyboard, and reverts to the SPCL menu.  Reverts to the SPCL menu, leaving the old serial number intact. Hvlin Menu This menu sequence is obtained by selecting Hvlin from the SPCL menu. It allows the linearity of the 1kV DC range to be adjusted with the application of five input signals of -1000V, -500V, 0V, +500V and +1000V in turn, with the 1kV DC range selected. On entry to the menu, the user is prompted to apply the first input signal required and step through the sequence:

adj135f.eps Hvlin Menus Pressing the SAMPLE key initiates the adjustment operation at the signal level displayed for the step in progress and; also, saves the result for calculation of the Hvlin linearity correction factor at the end of the sequence.  Moves back to the previous menu allowing the user to repeat the previous step in the sequence if required.  Moves forward through the sequence to the next step and signal level.  Initiates calculation and storage of the high voltage linearity correction factor, completing the Hvlin adjustment process.

Adjustment and Verification

Non-volatile input offset compensation 6

6-9 Non-volatile input offset compensation Good metrology practice should ensure that all high-precision measurements made with the 8508A are preceded by an input zero of each measurement. However, a non-volatile input-offset compensation is independently available for the front and rear inputs. This compensation is retained after power down and is unaffected by clearing the volatile input zeros. It is cleared by performing range zero adjustments. Compensation is available on all functions, and includes separate compensation of 2-wire and 4-wire measurements in the resistance functions. Non-volatile input-offset compensation adjustment is available only when the rear panel calibration keyswitch is in the ENABLE position and the CAL legend is not shown on the main display. Adjustment is performed by initiating an input zero operation with the 8508A in this condition, using the INPUT menu as described in Chapter 3 or using the IEEE 488 input zeroing commands described in Chapter 4. Apply a high-integrity low-thermal emf 4- wire short to the input terminals for this operation. Following adjustment for a particular combination of function, range, and input a compensation is stored for the corresponding non-volatile input zero, and the Zero legend is shown on the main display. The Zero legend may be removed from the display without affecting the stored non-volatile compensation by using one of the following operations:

8508A

Adjustment and Verification

Routine Adjustment 6

6-11 Preparing for Adjustment The following procedures represent the recommended order of adjustment, giving all the necessary setup commands.

8508A

Dcv

Acv

Dci

Aci

Adjustment and Verification

Routine Adjustment 6

6-13

Current

Output

Hi

Lo

Current

Output

Hi

Lo

8508A Reference M Ultim Eter

8508A-7000K

Pm

8508A - 7000K

4 W Short

4 10590 - A

adj381f.eps Figure 6-1. Equipment Connections Required for Calibration

8508A

Standby.

Adjustment and Verification

Routine Adjustment 6

6-15 Range Zero and Gain Adjustment Procedure After the initial setup and connecting up, use the following procedure to adjust range zero, then positive and negative range gains on all DCV ranges. Just one range can be adjusted if required, but for a full adjustment start with the 200 mV range and work up to the 1kV range, as shown in Table 6-3. Table 6-3. DC Voltage Adjustment Points and Sequence 8508A Range Point Voltage 200 mV

Zero 0 mV Range Gain +ve +100 mV -1 digit -0.00001 mV Range Gain -ve -100 mV

2 V

0 V

+1 V

-0.0000001 V

-1 V

20 V

0 V

+10 V

-0.000001 V

-10 V

200 V

0 V

+100 V

-0.00001 V

-100 V

1000 V

0 V

+1000 V

-1000 V

8508A

Adjustment and Verification

Routine Adjustment 6

6-17 AC Voltage Adjustment  Warning The Calibrator can deliver a lethal electric shock. To avoid electric shock when performing the following adjustment procedures: • Never touch any lead or terminal unless you are absolutely certain that no dangerous voltage is present. • Make sure that signal leads are in a safe condition before you handle them in any way Initial Setup and Connections

8508A

Zero (5 % Range) 10 mV 1 kHz Range Gain LF 100 mV 1 kHz Range Gain HF 100 mV 60 kHz

2 V

1V

1V

20 V

10 V

10 V

200 V

1 V

100 V

100 V

1000 V1

5 V

500 V

500 V

Adjustment and Verification

Routine Adjustment 6

6-19

Resistance Adjustment When adjusting the resistance function, each of the resistance modes (Normal, LoI, TruΩ, TruΩ LoI and HiVΩ) must be individually adjusted. The following procedure assumes use of a multifunction calibrator and adjusts each resistance mode in turn, range by range. If individual standard resistors are used it may be more convenient to adjust all the modes in turn for each resistance value to avoid connecting the same resistance standard several times during the adjustment sequence. A 1GΩ standard resistor provided in the 8508A-7000K Calibration kit is used for ranges above 200 MΩ as the highest resistance available from the 5720A calibrator is 100 MΩ. In order to minimize connection changes it is recommended that all adjustments using the 1 GΩ Standard resistor are performed together after all other resistance points.

8508A

2 Ω

Normal, Normal LoI, TruΩ, TruΩ LoI Zero

0 Ω

1 Ω

20 Ω

0 Ω

10 Ω

200 Ω

0 Ω

100 Ω

0 Ω

0 Ω

0 Ω

2 Mω

0 Ω

1 Mω

20 Mω

0 Ω

10 Mω

200 Mω

0 Ω

100 Mω

2 Gω

0 Ω

1 Gω

20 Gω

0 Ω

Adjustment and Verification

Routine Adjustment 6

6-21 Initial Setup and Connections

8508A

Adjustment and Verification

Routine Adjustment 6

6-23 Range Zero and Gain Points

8508A

Adjustment and Verification

Routine Adjustment 6

6-25 Range Zero and Gain Points

8508A

Adjustment and Verification

Routine Adjustment 6

6-27 Range Zero and Gain Points

Note For the 20MΩ range use 4 wire, for 200MΩ, 2GΩ and 20GΩ ranges use 2 wire mode on both the Calibrator and 8508A.

8508A

Adjustment and Verification

Routine Adjustment 6

6-29 Table 6-6. DC Current Adjustment Points and Sequence 8508A Range Point Current 200 μA

Zero 0 μA Range Gain +ve +100 μA Range Gain -ve -100 μA 2 mA Zero 0 mA Range Gain +ve +1 mA Range Gain -ve -1 mA 20 mA Zero 0 mA Range Gain +ve +10 mA Range Gain -ve -10 mA 200 mA Zero 0 mA Range Gain +ve +100 mA Range Gain -ve -100 mA

2 A

0 A

+1 A

-1 A

20 A

0 A

+10 A

-10 A

8508A

Adjustment and Verification

Routine Adjustment 6

6-31 Range Zero and LF Gain Adjustment Procedure After the initial setup and connecting up, use the following procedure to adjust range zero then range gain on all ACI ranges at the currents and frequencies detailed in Table 6-7. Just one range can be adjusted if required, but for a full-adjustment start with the 200 µA range and work up to the 20A range. Table 6-7. AC Current Adjustment Points and Sequence 8508A Range Point Current Frequency 200 μA

Zero (5 % Range) 10 μA 305 Hz Range Gain 100 μA 305 Hz 2 mA Zero (0.5 % Range) 10 μA 305 Hz Range Gain 1 mA 305 Hz 20 mA Zero (0.5 % Range) 100 μA 305 Hz Range Gain 10 mA 305 Hz 200 mA Zero (5 % Range) 10 mA 305 Hz Range Gain 100 mA 305 Hz

2 A

1 A

20 A

1 A

10 A

8508A

Adjustment and Verification

Routine Adjustment 6

6-33 Set Cal Due Date

8508A

Calibration Mode Disable

Adjustment and Verification

Performance Verification 6

6-35 To Adjust at Spot Frequencies Spot Adjustment is available only when in AC Voltage function with Spot already selected on the ACV CONFIG menu. Each spot (six per range) can be adjusted at a valid input frequency to a non-nominal RMS value. In subsequent use, frequency response flatness errors are reduced within ±10 % of the adjusted spot frequency. Set up and connect the 8508A as described under AC Voltage Adjustment, Initial Setup and Connections. The configuration defaults to Tfer and RESL6 (both required). Proceed as follows:

8508A

Adjustment and Verification

Performance Verification 6

6-37 DC current, Ohms and Temperature function verifications.) It is recommended that the 8-digit resolution mode be used if performance verification shows a borderline out-of- tolerance condition. In such cases 8-digit mode can be selected and the specifically borderline verification tests can be repeated. This will provide additional confidence in the in-tolerance or out-of-tolerance decision made during verification.

8508A

Adjustment and Verification

Performance Verification 6

6-39 Table 6-8. DC Voltage Verification Points and Sequence 8508A Range Voltage Tolerance 1 200 mV

0 mV Perform input zero operation to calibrator range locked zero output +100 mV ± 0.00072 mV -0.00001 mV Perform input zero operation to calibrator range locked -1d output -100 mV ± 0.00072 mV

2 V

0 V

+1 V

± 0.0000045 V

-0.0000001 V

-1 V

± 0.0000045 V

20 V

0 V

+1 V

± 0.000009 V

+10 V

± 0.000045 V

+19 V

± 0.000081 V

-0.000001 V

-1 V

± 0.000009 V

-10 V

± 0.000045 V

-19 V

± 0.000081 V

200 V

0 V

+100 V

± 0.00065 V

-0.00001 V

-100 V

± 0.00065 V

1000 V

0 V

+1000 V

± 0.0066 V

-1000 V

± 0.0066 V

8508A

Adjustment and Verification

Performance Verification 6

6-41 Table 6-9. AC Voltage Verification Points and Sequence 8508A Range Voltage Frequency 8508A Filter Tolerance 1 200 mV

100 mV 20 Hz 10 Hz ± 0.0195 mV 100 mV 55 Hz 40 Hz ± 0.0175 mV 100 mV 1 kHz 40 Hz ± 0.0149 mV 100 mV 3 kHz 40 Hz ± 0.0175 mV 100 mV 10 kHz 40 Hz ± 0.0175 mV 100 mV 30 kHz 40 Hz ± 0.0445 mV 100 mV 60 kHz 40 Hz ± 0.0995 mV 100 mV 100 kHz 40 Hz ± 0.0995 mV

2 V

1 V

± 0.000144 V

1 V

± 0.000119 V

1 V

± 0.000099 V

1 V

± 0.000119 V

1 V

± 0.000119 V

1 V

± 0.000295 V

1 V

± 0.000795 V

1 V

± 0.000795 V

1 V

± 0.034000 V

1 V

± 0.034000 V

20V

1 V

± 0.00032 V

10 V

± 0.00144 V

10 V

± 0.00119 V

10 V

± 0.00099 V

10 V

± 0.00119 V

10 V

± 0.00119 V

10 V

± 0.00295 V

10 V

± 0.00795 V

10 V

± 0.00795 V

10 V

± 0.34000 V

10 V

± 0.34000 V

19 V

± 0.00167 V

8508A

Table 6-9. AC Voltage Verification Points and Sequence (cont) 8508A Range Voltage Frequency 8508A Filter Tolerance 1

200V

100 V

± 0.0144 V

100 V

± 0.0119 V

100 V

± 0.0099 V

100 V

± 0.0119 V

100 V

± 0.0119 V

100 V

± 0.0295 V

100 V

± 0.0795 V

100 V

± 0.0795 V

1000 V

500 V

± 0.088 V

500 V

± 0.088 V

500 V

± 0.088 V

500 V

± 0.088 V

500 V

± 0.223 V

1000 V

± 0.331 V

1000 V

± 1.476 V

Adjustment and Verification

Performance Verification 6

6-43 Equipment Configuration

8508A

8508A.)

Adjustment and Verification

Performance Verification 6

6-45 Table 6-10. Resistance Verification Points and Sequence 8508A Range Resistance Tolerance 1 Normal Ω and TruΩ2 Normal Ω LoI and TruΩ LoI2

2 Ω

0 Ω

1 Ω

± 0.0000240 Ω

± 0.0000240 Ω

20 Ω

0 Ω

10 Ω

± 0.000133 Ω

± 0.000133 Ω

200 Ω

0 Ω

100 Ω

± 0.00101 Ω

± 0.00113 Ω

2 Mω

0 Mω

1 Mω

± 0.0000117 Mω

± 0.0000142 Mω

20 Mω

0 Mω

10 Mω

± 0.000320 Mω

± 0.000570 Mω

200 Mω

0 Mω

100 Mω

± 0.01950 Mω

± 0.18700 Mω

2 Gω

0 Gω

1 Gω

± 0.0018750 Gω

± 0.0018750 Gω

8508A

20 Mω

0 Gω

10 Mω

± 0.000202 Mω

200 Mω

0 Gω

100 Mω

± 0.00870 Mω

2 Gω

0 Gω

1 Gω

± 0.0003150 Gω

20 Gω

0 Gω

1 Gω

± 0.012675 Gω

Adjustment and Verification

Performance Verification 6

6-47

0 μA Perform input zero operation to calibrator range locked zero output +100μA ± 0.00190 μA -100μA ± 0.00190 μA 2 mA 0 mA Perform input zero operation to calibrator range locked zero output +1mA ± 0.0000190 mA -1mA ± 0.0000190 mA 20 mA 0 mA Perform input zero operation to calibrator range locked zero output +10mA ± 0.000200 mA -10mA ± 0.000200 mA 200 mA 0 mA Perform input zero operation to calibrator range locked zero output +100mA ± 0.00530 mA -100mA ± 0.00530 mA

2 A

0 A

+1A

± 0.0002260 A

-1A

± 0.0002260 A

20 A

0 A

+10A

± 0.004950 A

-10A

± 0.004950 A

8508A

Adjustment and Verification

Performance Verification 6

6-49 Table 6-12. AC Current Verification Points and Sequence 8508A Range Current Frequency Tolerance 1 200 μA 100 μA 305 Hz ± 0.0830 μA 100 μA 1 kHz ± 0.0830 μA 100 μA 3 kHz ± 0.0830 μA 100 μA 5 kHz ± 0.0830 μA 100 μA 10 kHz ± 0.0830 μA 2 mA 1 mA 305 Hz ± 0.000580 mA 1 mA 1 kHz ± 0.000580 mA 1 mA 3 kHz ± 0.000580 mA 1 mA 5 kHz ± 0.000580 mA 1 mA 10 kHz ± 0.000580 mA 20 mA 10 mA 305 Hz ± 0.00580 mA 10 mA 1 kHz ± 0.00580 mA 10 mA 3 kHz ± 0.00580 mA 10 mA 5 kHz ± 0.00580 mA 10 mA 10 kHz ± 0.00580 mA 200 mA 100 mA 305 Hz ± 0.0545 mA 100 mA 1 kHz ± 0.0545 mA 100 mA 3 kHz ± 0.0545 mA 100 mA 5 kHz ± 0.0545 mA 100 mA 10 kHz ± 0.0545 mA

2 A

1 A

± 0.000945 A

1 A

± 0.000945 A

1 A

± 0.001055 A

1 A

± 0.001055 A

1 A

± 0.001055 A

20 A

10 A

± 0.01140 A

10 A

± 0.01140 A

10 A

± 0.02740 A

10 A

± 0.02740 A

10 A

± 0.02740 A

8508A

A-1

8508A

A-2

Appendix

Error Codes and Message A

A-3

2005- Error During LoI Zero Cal

2006- Error During LoI Gain Cal

2008- Error During A to D Cal 2010- Error During Frequency Cal 2012- Error During DCcp Cal 2025- Error During HiV Lin Read 2026- Error During HiV Lin Calc Corruptions 2014- Serial Number Corrupt 2015- Cal Due Date Corrupt 2017- Bus Address Corrupt 2018- Line Frequency Corrupt 2020- Invalid Corrections (ram) 2021- Calibration Corrupt 2022- NV RAM Write Failure

8508A

A-4

Appendix

Error Codes and Message A

A-5

8508A

A-6

B-1

8508A

B-2

adj359f.eps Figure B-1. Installing the 8508A Rack Mount Kit

C-1

8508A

C-2

adj362f.eps Figure C-1. Installing the 8508A Rack Mount Slide Kit