Fluke 8506A User manual

This manual documents Model 8506A and Its assemblies at the revision levels shown in Appendix 7A. If
your instrument contains assemblies with different revision letters, It will be necessary for you to either
update or backdate this manual. Refer to the suppfemertfa! change/errata sheet for newer assemblies,
or to the backdating sheet in Appendix 7A for older assemblies. ........ /v" ...
..*••• y«. ;.
*•.. ..
P/N 638858
MARCH 1983 Rev 1. 10/85
©1985, John Fluke Mfg. Co., Inc., ail rights reserved. Litho in USA.

Notwithstanding any provision of any agreement the following warranty :sexclusive-
The JOHN FLUKE MFG. CO INCT. warrants each instrument it manufactures to be free from defects in material and
workmanship under normal use and service for the period of 1-year from date of purchase. This warranty extends only
to the original purchaser This warranty shall not apply to fuses, disposable batteries (rechargeable type batteries are
warranted for 90-days), or any product or parts which have been subject to misuse, neglect, accident, or abnormal
conditions of operations.
In the event of failure of aproduct covered by this warranty, John Fluke Mfg. Co., Inc., will repair and calibrate an
instrument returned to an authorized Service Facility within 1year of the. original purchase; provided the warrantor's
examination discloses to its satisfaction that the product was defective. The warrantor may, at its option,- replace the
product in lieu of repair With regard to any instrument returned within 1year of the original purchase, said repairs or
replacement will be made without charge. If the failure has been caused by misuse, neglect, accident, or abnormal
conditions of operations, repairs will be billed at anominal cost. In such case, an estimate will be submitted before
work is started, if requested.
THE FOREGOING WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS.
OR ADEQUACY FOR ANY PARTICULAR PURPOSE OR USE. JOHN FLUKE MFG CO., INC., SHALL
NOT BE LIABLE FOR ANY SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WHETHER IN
CONTRACT, TORT, OR OTHERWISE.
if any failure occurs, the following steps should be taken;
1Notify the JOHN FLUKE MFG CO., INC., or nearest Service facility, giving full details of the difficulty, and
include the model number, type number, and serial number. On receipt of this information, service data, or
shipping instructions will be forwarded to you.
2. On receipt of the shipping instructions, forward the instrument, transportation prepaid. Repairs will be
made at the Service Facility and the instrument returned, transportation prepaid.
SHIPPING TO MANUFACTURER FOR REPAIR OR ADJUSTMENT
All shipments of JOHN FLUKE MFG. CO., INC., instruments should be made via United Parcel Service or "Best Way"*
prepaid. The instrument should be shipped in the original packing carton; or if it is not available, use any suitable
container that is rigid and of adequate size. If asubstitute container is used, the instrument should be wrapped in paper
and surrounded with at least four inches of excelsior or similar shock-absorbing material.
CLAIM FOR DAMAGE iN SHIPMENT TO ORIGINAL PURCHASER
The instrument shoula be thoroughly inspected immediately upon original delivery to purchaser. All material in the
container should be checked against the enclosed packing list. The manufacturer will not be responsible for shortages
against the packing sheet unless notified immediately. If the instrument is damaged in any way, aclaim should be filed
with the carrier immediately. (To obtain aquotation to repair shipment damage, contact the nearest Fluke Technical
Center.) Final claim and negotiations with the carrier must be completed by the customer.
The JOHN FLUKE MFG. CO., INC, will be happy to answer all applications or use questions, which will enhance your
use of this instrument. Please address your requests or correspondence to: JOHN FLUKE MFG. CO., INC., P.O. BOX
C9090, EVERETT, WASHINGTON 98206, ATTN; Sales Dept. For European Customers; Fluke (Holland) B.V., P.O. Box
5053, 5004 EB, Tilburg, The Netherlands.
*For European customers, Air Freight prepaid.
John Fluke Mfg. Co., Inc., P.O. Box C9030, Everett, Washington 98208
Rev. 6/81

cw&FjMmsA immmsim
issm Mis i3/ a>
This change/errata contains information necessary to ensure the accuracy of
the foilwing manual. Enter the corrections in the manual if either one or-
the foilwing conditions exists
'1. The revision letter stamped on the indicated PCS is equal to or
higher than that given with each change.
2. No revision letter is indicated at the beginning of the change/ertata
mna
Title; 8506A
Print Date. March 1983
Rev.- Date; 1-10/ 85
C/E BBSE EFEBCTtemT
Page No* Print Date
3/85
1

8506A
RKRMA #1
On page 1-1, preceeding paragraph 1-5, add the following NOTE,
NOTE
The A3 Isolator PCB is standard in the 8506A. This
assembly is documented in Section 6of this manual as
Option -08A.
On page 5-1, reverse the FIGURE and PAGE column headings.
On pages 608A-5 and 60 8A-6, disregard Table 608A-3 and refer to Table
5-4.
On pages 60 8A-7 and 608A-8, disregard Figure 608A-3 and refer to Figure
8-3
«
-1-
3/86

8506A
Table of Contents
SECTION TITLE PAGE
1INTRODUCTION AND SPECIFICATIONS 1-1
1-1. INTRODUCTION .....1-1
1-3. DESCRIPTION l-l
1-5. Thermal True-RMS Conversion 1-1
1-7. Modular Construction 1-1
1-9. Microprocessor Control 1-1
1-11. Software Calibration 1-1
1-13. Recirculating Remainder A/D Conversion 1-1
1-15. Options and Accessories 1-1
1-
17. SPECIFICATIONS 1-1
2OPERATING INSTRUCTIONS 2~1
2-
1. INTRODUCTION 2-1
2-3. SHIPPING INFORMATION 2-1
2-6. INSTALLATION 2-1
2-9. OPERATING FEATURES ....2-1
2-11. OPERATING NOTES 2-1
2-12. Input Power 2-1
2-14. Fuse Location 2-1
2-16. Required Hardware 2-4
2-20. Power-Up Configuration 2-4
2-22. Display 2-6
2-46. Front Panel Push Buttons 2-10
2-53. Measurement Terminals and Controls 2-21
2-69. Function 2-22
2-72. Measurement Parameters 2-24
2-102. Mathematic Operations 2-26
2-115. Special Operations 2-27
2-124. Remote Control 2-28
2-128. Calibration Mode 2-28
2-138. Scan Advance 2-29
2-140. Systems Use 2-29
2-142. OPERATION 2-29
2-143. Initial Turn-On 2-29
2-147. Initial Set-Up 2-29
2-152. Measurement Instructions 2-30
2-170. APPLICATIONS 2-32
i(continued on page ii)

8506A
TABLE OF CONTEMTS, continued
SECTION TITLE PAGE
2A REMOTE PROGRAMING COMMANDS 2A-1
3THEORY OF OPERATION 3-1
3-1. INTRODUCTION 3-1
3-3. BLOCK DIAGRAM DESCRIPTION 3-1
3-4. Bus Structure 3-1
3-10. Controller 3-2
3-20. Front Panel 3-6
3-22. DC Signal Conditioner 3-6
3-24. Active Filter 3-6
3-26. Fast R2A/D Converter 3-6
3-31. Thermal True-RMS Converter 3-8
3-40. Front/ Rear Switch Assembly 3-10
3-42. CIRCUIT ANALYSIS ..3-10
3-43. Introduction 3-10
3-45. Controller 3-10
3-65. Front Panel 3-13
3-68. DC Signal Conditioner 3-15
3-72. Filter/ External Reference 3-15
3-76. Fast R2A/D Converter 3-15
3-90. Thermal True RMS-Converter Module 3-20
4MAINTENANCE 4-1
4-1. INTRODUCTION 4-1
4-3. SERVICE INFORMATION 4-1
4-6. GENERAL MAINTENANCE 4-1
4-7. Top and Bottom Cover Removal and installation 4-1
4-9. Line Voltage Selection 4-1
4-11. Fuse Replacement 4-1
4-13. Module Installation 4-4
4-15. Module Removal 4-4
4-17. Module Disassembly and Reassembly 4-4
4-19, Calibration Memory Replacement 4-4
4-21. Front Panel PCB Removal 4-5
4-23. Power Supply PCB Assembly Removal 4-5
4-25. Power Supply Interconnect Assembly Removal 4-5
4-27. Front/ Rear Switch Assembly 4-5
4-32. Motherboard PCB Removal .4-6
4-34. Cleaning Instructions 4-6
4-36. PERFORMANCE TEST 4-6
4-37. Introduction 4-6
4-40. DC Performance Test 4-7
4-49. Thermal True-RMS Converter Performance Test 4-9
4-54. CALIBRATION ADJUSTMENTS 4-17
4-55. Introduction 4-17
4-57. Initial Procedure 4-17
4-59. Power Supply 4-1?
4-61. DC Calibration Procedure 4-18
4-85. AC Calibration Procedure 4-21
4-108. TROUBLESHOOTING 4-26
4-114. Troubleshooting Notes 4-28
4-119. Non-recurring Adjustments 4-28
4-130. Factory Selected Component Replacement Procedures 4-45
4-142. SELECTED CAPACITOR ORDERING INFORMATION 4-47
ii (continued on page Hi)

8506A
TABLE OF CONTENTS, continued
SECTION TITLE PAGE
5LIST OF REPLACEABLE PARTS .5-1
TABLE OF CONTENTS 5-1
5- 1.INTRODUCTION 5-2
5-4. HOW TO OBTAIN PARTS 5-2
8OPTION AND ACCESSORY INFORMATION 6-1
TABLE OF CONTENTS 6-1
7GENERAL INFORMATION .... 7-1
7A MANUAL CHANGE INFORMATION 7A~1
78 SOFTWARE CALIBRATION 7B-1
8SCHEMATIC DIAGRAMS 8-1
TABLE OF CONTENTS 8-1
Hi

8506A
TITLE
1-1. Options 1-2
1-2. Accessories 1-2
1-
3. Specifications 1-2
2-
1. Controls, Indicators, and Connectors 2-2
2-2. Default Configurations 2-5
2-3. Display 2-7
2-4. Operating Ranges 2-8
2-5. Error Codes 2-9
2-6. Filter Modes (VDC, ADC, OHMS) 2-25
2-7. Resolution 2-26
2-
8. Applications 2-32
2A-I. Programming Instructions 2A-2
2A-2. Programming Instructions (8505A, 8506A) 2A-22
3-
1. Mnemonics 3-10
3-2. Module Commands Logic 3-22
3-
3. Decoded ID Bus Logic 3-22
4-
1. Test Equipment 4-2
4-2. Low Range DC Voltage Tests 4-7
4-3. Autoranging 4-8
4-4. Characterization Points 4-11
4-5. 110 mV Tests 4-12
4-6. 390 mV on the 300 mV Range Tests 4-14
4-7. 390 mV on the 3V Range Tests 4-15
4-8. IV on the IV Range Tests 4-15
4-9. 3.9V on the 3V Range Tests 4-15
4-10. 3.9V on the 30V Range Tests 4-15
4-11. I0V on the 10V Range Tests 4-15
4-12. 35V on the 30V Range Tests 4-16
4-13. 100V on the I00V Range Tests 4-16
4-14. 100V on the 500V Range Tests 4-17
4-15. 300V on the 500V Range Tests 4-17
4-16. Power Supply Verifications 4-17
4-17. Linearity Checks 4-20
4-18. Amplifier and Attenuator Adjustments 4-23
4-19. Faulty Module Isolation 4-30
4-20. Controller Troubleshooting 4-34
4-21. Front Panel Troubleshooting 4-34
4-22. DC Signal Conditioner Troubleshooting 4-35
4-23. Active Filter Troubleshooting 4-36
4-24. R2A/D Converter Troubleshooting 4-37
iv (continued on page v)

8506A
LIST OF TABLES, continued
TABLE TITLE PAGE
4-25. Thermal True-RMS Converter Module Troubleshooting 4-39
4-26. RMS Sensor Troubleshooting and Replacement 4-42
4-27. Thermal True-RMS Converter Typical Test Voltages 4-44
4-28. Thermal True-RMS Converter Attenuator Logic Table 4-44
4-29. Amplifier Offset Resistor Selection 4-45
4-30. C7 Selection Values 4-46
4-31. C18 Selection Values 4-46
4-32. C25 Selection Values 4-47
4-33. C26 Selection Values 4-47
4-34. Ordering Information for Selected Capacitors 4-48
v

Frontispiece 85G6A Thermal True RMS Multimeter .viii
FI. Dimension Drawing 1-10
2-1. Controls, indicators, and Connectors 2-2
2-2. Front Panel Push Buttons 2-11
2-3. Programming Hierarchy 2-17
2-4. Guard Connections 2-22
2-
5. Measurement Connections 2-23
3-
1. Block Diagram ........... 3-1
3-2. Analog Signal Flow 3-2
3-3. Background Software Process 3-3
3-4. Foreground Software Process 3-4
3-5. Controller Block Diagram 3-5
3-6. DC Signal Conditioner Block Diagram 3-6
3-7. Active Filter Block Diagram 3-7
3-8. R2A/D Converter Block Diagram 3-7
3-9. Ideal Curve 3-8
3-10. Thermal True RMS Functional Block Diagram 3-9
3-11. Timing Circuits 3-11
3-12. Reset Logic 3-11
3-13. Status Latch ......... 3-1
1
3-14. Wait Logic 3-12
3-15. ACK Panel 3-12
3-16. Interrupt Generation Logic 3-13
3-1 7. Front Panel 3-14
3-18. DC Signal Conditioner 3-16
3-19. Filter/ External Reference 3-17
3-20. Fast R2A/DConverter (Analog) 3-19
3-
21. Thermal True-RMS Conversion 3-21
4-
1. Power Supply Settings 4-3
4-2. Connections for Low Range DC Voltage Tests 4-7
4-3. Connections for High Range DC Voltage Tests 4-8
4-4. DC External Reference Test 4-9
4-5. Equipment Set-Up A4-10
4-6. Equipment Set-Up B4-12
4-7. Equipment Set-Up C4-13
4-8. Equipment Set-Up D4-14
4-9. Equipment Set-Up E...... 4-16
vi (continued on page vii)

8506A
LIST OF ILLUSTRATIONS, continued
FIGURE TITLE PAGE
4-10. Equipment Set-Up F4-24
4-1 1. Equipment Set-Up G4-25
4-12. Equipment Set-Up H4-26
4-13. Power Supply Troubleshooting 4-38
vii

8506A
Section 1
ntroduction &Specifications
1-1. INTRODUCTION
1-2. This eight-section manual provides comprehensive
information for installing, operating and maintaining
your Fluke digital multimeter. Complete descriptions and
instructions are included for the instrument mainframe,
for all modules necessary in making thermal true-rms and
dc volts measurements, and for any optional modules
ordered with the instrument. Appropriate sectionalized
information is included with any optional modules
subsequently ordered and may be inserted in Section 6.
1-3. DESCRIPTION
1-4. The multimeter features 6-1 /2digit resolution, full
annunciation and simplicity of operation. Modular
construction, microprocessor control, and abus structure
provide excellent flexibility. Memory programming from
the front panel (or through aremote interface) controls all
measurement parameters, mathematical operations and
special operations. The standard hardware configuration
allows for measurement of thermal true-rms volts on
eight ranges and dc volts in five ranges. An averaging
mode is available to automatically optimize display
resolution and stability for each range in dc volts,
resistance, and dc current functions. Extended resolution
is also available in the ac volts function. Optional
modules are available for dc current (five ranges), and
resistance (eight ranges) in two-wire or four-wire
arrangements.
1-5. Thermal True-RMS Conversion
1-6. The thermal true-rms feature allows the operator to
measure the true-rms value of an ac signal at accuracies of
up to .012% with areading rate of one every six seconds.
This response time compares favorably with that of
existing thermal transfer standards which can take up to
five minutes to complete ameasurement.
1-7. Modular Construction
1-8. Considerable versatility is realized through unique
modular construction. All active components are
contained in modules which plug into amainframe
motherboard. This module-to-motherboard mating,
combined with bus architecture and microprocessor
control, yields ease of option selection.
1-9. Microprocessor Control
1-10. All modules function under direct control of a
microprocessor based controller. Each module is
addressed by the controller as virtual memory. Scaling
factors and offset values can be applied separately, stored
in memory, and automatically used as factors in all
subsequent readings. Digital filtering utilizes averaged
samples for each reading.
1-11. Software Calibration
1-12. The 8506A features microprocessor-controlled
calibration of all ranges and functions. Any range can be
calibrated using areference input of any known value
from 60% of range to full scale. Software calibration can
be performed using front-panel or remote control,
allowing recertification without opening the case or
removing the multimeter from the system.
1-13. Recirculating Remainder A/D Conversion
1-14. The multimeter adapts Fluke’s patented
recirculating remainder (R2)A/D conversion technique
to microprocessor control. This combination provides
fast, accurate, linear measurements and long-term
stability.
1-15. Options and Accessories
1-16. Remote interfaces, adc current converter, and an
ohms converter are among the options and accessories
available for use with the multimeter. Refer to Tables i-i
and 1-2 for complete listings. Any one of the three
Remote Interface modules (Option 05, 06, or 07) may be
installed at one time.
1-17. SPECIFICATIONS
1-18. Mainframe specifications for ac volts, dc volts and
dc ratio measurement capability are presented inTable 1-3.
Optional function specifications are supplied with the
respective option modules and included in Section 6.
1-1

02A Ohms Converter
03 Current Shunts
05 IEEE Standard 488-1 975 Interface
06 Bit Serial Asynchronous '
07 Parallel Interface
1} Either Option 02A or Option 03 can
be installed at one time.
2} Only one of Options 05. 06. and 07
a
M04-205-600 S’A-inch Rack Adapter
MOO-260-61 018-inch Rack Slides
MOO-280-610 24-inch Rack Slides
80K-6 High Voltage Probe
80K-40
83RF
85RF
Y8021
Y8022
Y8023
629170
High Frequency Probe
II
Y8022 IEEE Std. Cable, 2Meter Length
Y8023 IEEE Std. Cable, 4Meter Length
629170 TRMS Extender Card
MIS-71 90K* Static Controller
MIS-7013K* Bus interconnect and Monitor
*For use during service or repair.
ecmcations
GENERAL SPECIFICATIONS
Dimensions —10.8 cm High x43.2 cm Wide x42.5 cm Long
(4.25 in High x17 in Wide x16.75 in Long) (See Figure 1-1)
Weight
BASIC .... 10 kg (22 lbs)
FULLY LOADED .... 12 kg (26 lbs)
Operating Power
VOLTAGE ... . 100V ac, 120V ac, 220V ac, or 240V ac (±10%)
BASIC INSTRUMENT POWER ..
.
. . . . 12 watts
FULLY LOADED POWER 24 watts
FREQUENCY 47 Hz to 63 Hz (400 Hz available on request)
Warm-Up ....2hours to rated accuracy
Shock and Vibration —Meets requirements of MIL-T-28800 for type III, class 5,
style Eequipment.
Temperature Rang©
OPERATING .... 0°C to 50°
C
NON-OPERATING .... -40° Cto 70°
C
Humidity Range
0° CTO 18° C.... 80% RH
18°C TO 40° C. . ..75% RH
40° CTO 50° C... . 45% RH
Maximum Terminal Voltage
LO TO GUARD .... 127V rms
GUARD TO CHASSIS .... 500V rms
H! SENSE TO Hi SOURCE 127V rms
LO SENSE TO LO SOURCE .... 127V rms
Hi SENSE TO LO SENSE 1000V rms or 1200V dc
HI SOURCE TO LO SOURCE . . .
.
280V rms
-2

Table 1-3. Specifications (cent)
AC VOLTAGE
input Characteristics
FULL SCALE
5'A DIGITS
100 mV 125.000 mV
300 mV 400.000 mV
IV 1.25000V
3V 4.00000V
10V 12.5000V
30V
100V
500 V800.000V
RESOLUTION
6V2DIGITS* 5% DIGITS
1(M
1jjV
10 fjV
10 //V
100 //V
100 mV
1mV
1mV
*ln AVG operating mode.
Accuracy
HIGH ACCURACY MODE ±(% of Reading +Number of Counts)
1
INPUT IMPEDANCE
1MQ
±1%
Shunted by
<180 pF
24 HOUR: 23° C±1°C2
FREQUENCY IN HERTZ
RANGE 10 TO
40*
40 TO
20k
20k TO
50k
50k TO
100k
100k TO
200k
200k TO
500k
500k TO
1M
100 mV 0.08 +00.02 450.04 +50.2 4- 00.6 401.5 403.5 40
300 mV to
10V 0.08 400.012 400.04 400.2 400.5 401.5 403.5 40
30V 0.08 400.012 +00.04 4- 00.2 400.5 403.5 4012 40
100V0.08 +00.012 +00.04 400.2 401.0 403.5 40—
500V30.08 +00.012 400.04 400.2 40———
90 DAY: 23° C±5°C
FREQUENCY IN HERTZ
10 TO
40* 40 TO
20k
20k TO
50k
50k TO
100k
100k TO
200k
200k TO
500k
500k TO
1M
100 mV 0.08 400.026 450.06 400.2 400.6 401,5 403.5 40
300 mV to
10V 0.08 400.016 400.06 400.2 400.5 401.5 403.5 40
30V 0.08 400,016 400.06 400.2 400.5 403.5 4012 40
100V 0.08 400.016 400.06 400.2 401.0 403.5 40—
500V30.08 400.016 400.06 400.2 40———
1-3

>90 DAY: 23° C±5°C
ADD TO THE 90 DAY SPECIFICATION PER MONTH THE FOLLOWING %OF READING
10 TO
40
40 TO
20k
20k TO
|50k
50k TO
100k
100k TO
200k |
200k TO
500k
500k TO
1M
0.008 0.001 10.06 0.11
NOTES:
1AC coupled, 5V2 digits, input level >0.25 xfull scale. For 6V6 digits multiply Number of Counts by 10.
For input levels between 0.1 xand 0.25 xfull scale, add 5counts for the 100 mV, IV, 10V, and 100V
ranges, add 15 counts for the 300 mV, 3V, 30V ranges, and add 25 counts for the 500V range.
2Relative to calibration standards, within 1hour of dc zero.
3Add 0.02 x(Input voltage /600) 2%of Reading to the specification.
ENHANCED MODE: Add thefollowing (% of Reading +Number of Counts) to the High Accuracy Mode
^Specifications.
RANGE TIME SINCE FIRST READING
...'
<5 MINUTES <30 MINUTES
100 mV, IV, 10V, 100V 0+00.003 +4
300 mV, 3V, 30V 0+0 0.003 +4
500V 0+00.003 +6
*AC-coupled, 5% digits, temperature change <1°C, input level >0.25 xfull scale. For input levels between
O.lx and 0.25x full scale, multiply %of Reading adder by 10.
NORMAL MODE: Add the foiiowing %of Reading to the High Accuracy Mode Specification.
SEGMENT OF SCALE >90 DAY ADD PER MONTH
Q.25x to lx full scale 0.4 0,044
O.lx to Q.25x full scale 0.6 0.055
AC+DC COUPLED MODES: ±(1.1 times the ac specification for the appropriate mode +the result (Adder)
from the following table).
RANGE ADDER
100 mV to IV ±(150 /A/ x(dc volts /total rms volts))
3V and 10V ±(1 mV x(dc volts /total rms volts))
30V and 100V ±(10 mV x(dc volts /total rms volts))
500V ±(50 mV x(dc volts /total rms volts))

Operating Characteristics
STABILITY: ±(1% of Reading +Number of Counts)’
100 mV, IV, 10V, 100V
300 mV, 3V, 30V
500V
24 HOUR 90 DAY
0.0025 +10.004 +1
0.0025 +30.004 +4
0.0025 +50.004 +6
‘High Accuracy Mode, ac coupled, 5Vs digits, input level >0.25xfull scale, 40 Hz to 20 kHz, temperature change
<1°C. For BVs digits, multiply Number of Counts by 10. For input levels between 0. lx and 0.25x full scale, add to
the Number of Counts specification 2counts for the 100 mV, 1V, 10V, and 100V ranges, 6counts for the 300 mV,
3V, and 30V ranges, and 10 counts for the 500V range.
CREST FACTOR ..
3dB BANDWIDTH
Up to 8:1 at full 90 day (or greater) accuracy for input signals with
peaks less than two times full scale, and highest frequency
components within the 3dB bandwidth. Up to 4:1 for signals with
peaks less than four times full scale, with an addition of 0.03 to the %of
Reading.
3MHz for the 100 mV range and 10MHz for the 300 mV, 1V, 3V and 10
V
ranges (typical).
MAXIMUM INPUT VOLTAGE ±600V rms or dc, 840V peak, or lx 107volts-hertz product
TEMPERATURE COEFFICIENT 0°C to 18°C and 28° Cto 50° C
1/10 of 90 day Specification per °C
COMMON MODE REJECTION >120 dB, dc to 60 hertz, with 1QQQ in series with either lead.
SETTLING TIME
High Accuracy Mode
Enhanced Mode
Normal Mode
Sample time =3.5 seconds
Hold time =2.5 seconds
Measurement time =6seconds
If the state of the instrument is unknown, two complete measurement
times will be required to guarantee acorrect reading. Use of the
external trigger mode will always allow a 6 second measurement time.
The first reading requires the same time as the High Accuracy Mode.
Subsequent readings occur every 500 milliseconds. If the input
changes 1% the analog settling time to 90 Day mid-band accuracy is
1.5 seconds.
Settling times for large changes are non-linear, Zero to Full Scale
changes require 2.0 seconds to settle to 90 Day, mid-band
specifications. Full scale to 1/1 0th full scale changes require 3.0
seconds to settle to 1/1 0th full scale, mid-band; 90 day specifications.
Small changes (<1%) settle to mid-band specifications in <1.5
seconds.
1-5

8506A
RANGE UPRANGE
100 mV 125.000 mV
300 mV 400.000 mV
IV 1.25000V
3V 4.00000V
10V 12.5000V
30V 40.0000V
100V 125.000V
500V None
RANGE UNDERRANGE
DISPLAY
LLLLL
MINIMUM
SPECIFIED
LEVEL
OVERRANGE
DISPLAY
HHHHH
100 mV None 12.5 mV 125.000 mV
300 mV 20 mV 40 mV
IV 62.5 mV 125 mV 1.25000V
3V 200 mV 400 mV
10V 625 mV 1.25V 12.5000V
30V 2V 4V
100V 6.25V %12.5V 125.000V
500V 30V 60V 600,000V
RANGE FULL SCALE
6V2DIGITS
100 mV 200.0000 mV
IV 2.000000V
10V 20.00000V
100V 128.0000V
1000V 1200.000V
RESOLUTION
Vh
DIGITS'*
6V2
DIGITS
100 nV
1/iV
10 fN
100 /j\J
1mV
>10,000MQ
>10,000MQ
>10,000MO
1QMQ
10MO
*7V&-digit resolution: In AVG operating mode.
1-6

8506A
Table 1-3. Specifications (con!)
100 mV
IV
10V
100V
1000V
DC VOLTS: ±(% of Reading +Number of Counts)
24-HOUR 90-DAY
23°C ±1°C123°C±5°C
OPERATING MODE
AVG
0.0018 +15
0.0008 +7
0.0006 or 6*
0.0010 +6
0.0008 +6
0.0010 +8
0.0005 +4
0.0005 or 50
2
*
0.0005 +5
0.0005 +5
OPERATING MODE
0.0025 +40
0.0015 +8
0.0010 +8
0.0018 +8
0.0018 +8
0.0020 +8
0.0012 +6
0.0008 +602
0.0015 +6
0.0015+6
"Whichever is greater
>90~Day: 23° C±5°C
Add to the 90-day specification per month the following %of Reading and Number of Counts.
OPERATING MODE
100 mV
IV
10V
100V
1000V
0.00017 +5.6
0.0001 +0.1
0.0001 +0.1
0.00013 +0.1
0.00013 +0.1
0.0001 +0.1
0.0001 +0.1
0.00008 +I2
0.0001 +0.1
0.0001 +0.1
’Relative to calibration standards, 4-hour warm-up, within 1hour of dc zero. After software calibration,
add the following to the 24 hour accuracy specification:
TIME SINCE INTERNAL NUMBER OF
(HARDWARE) CALIBRATION COUNTS*
<30 Days 0
<90 Days 1
<1 Year 2
>1 Year 3
"With 6V2“digit display. For 7Vfe-digits, multiply Number of Counts by 10.
27!6-digit mode of operation.
3After 4-hour warm-up, within 1hour of dc zero.
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Operating Characteristics
TEMPERATURE COEFFICIENT: ±(% of Reading +Number of Counts)/°C
RANGE
100 mV
IV
10V
100V
1000V
0°C TO 18°C AND 28°C TO 50°C
0.0003 +5
0.0003 +1
0.0002 +0.5*
0.0003 +1
0.0003 +0.5
"Multiply Number of Counts by 10 for AVG operating mode (7^-digit).
INPUT BIAS CURRENT
AT TIME OF ADJUSTMENT 1-YEAR 23° C±1°C r~TEMPERATURE COEFFICIENT
<±5 pA <±30 pA <±1 pA/°C
ZERO STABILITY
MAXIMUM INPUT VOLTAGE
Less than 5yuV for 90 days after a4-hour warm-up. Front panel ZERO
push button stores azero correction factor for each range.
±T200V dc or 1000V rms ac to 60 Hz, or 1400V peak above 60 Hz may
be applied continuously to any dc range without permanent damage.
Maximum common mode rate of voltage rise is 1000V ///sec.
ANALOG SETTLING TIME
FILTER TO 0.01% OF TO 0.001% OF
FILTER MODE COMMAND STEP CHANGE STEP CHANGE
Bypassed FI 2ms 20 ms
Fast F0 or F3 40 ms 50 ms
Slow For F2 400 ms 500 ms
DIGITIZING TIME
Line Synchronous
Line Asynchronous
For 2° to 217 samples per reading digitizing time is from 4ms to 9
minutes 6seconds using a60 Hz ac line with times increasing 20%
using a50 Hz ac line. Selectable in 18 binary steps.
2ms. (In 3byte binary mode with dc zero, offset, limits and calibration
factors turned off.)
NOISE REJECTION
Normal Mode Rejection
LINE FILTER 4SAMPLES/ 32 SAMPLES/ 128 SAMPLES/
FREQUENCY READING READING READING
50 hertz Fast 60 dB 70 dB 75 dB
50 hertz Slow 85 dB 90 dB 95 dB
60 hertz Fast 60 dB 70 dB 75 dB
60 hertz Slow 90 dB 95 dB 100 dB
Common Mode Rejection 160 dB at 60 hertz with 1kD in series with either lead, and 4samples or
more per reading, Greater than or equal to 100 dB with less than 4
samples per reading.
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