Fluke 732a User manual

NOTE
This manual documents the Model 732A and its assemblies at the revision levels shovwn 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 supplemental
change/errata sheet for newer assemblies, or to the backdating sheet In Appendix 7Afor
older assemblies.
For the benefit and convenience of its customers, Fluke
Corporation (Fluke) has reproduced this copy of amanual
which is no longer in production. This manual has not been
edited or updated since the revision date shown on the lower
left fiend corner of the ^rst pege. Fluke will not be liable for
any claims, losses or damages of any kind incurred by any
user arising from use of this manual.
732A
DC Reference
Standard
Instruction Manua
IFLUKE
P/N 645051
MAY 1983
«19S3, John Fluke Mfg. Co., Inc., all rights reserved. LUho in U.S.A.

732A
Table of Contents
SECTION TITLE PAGE
1INTRODUCTION AND SPECIFICATIONS 1-1
l-l. INTRODUCTION l-l
1-
8. SPECIFICATIONS M
2OPERATION 2-1
2-
1. INTRODUCTION 2-1
2-3. SHIPPING INFORMATION 2-1
2-7. INSTALLATION 2-1
2-9. FRONT AND REAR PANEL FEATURES 2-1
2-11. OPERATING NOTES 2-1
2-12. Introduction 2-1
2-14. Input Power Requirements 2-1
2-16. AC Line Voltage Selection 2-1
2-18. Fuse Replacement 2-1
2-20. Backup Operating Power 2-5
2-22. Battery Charging 2-5
2-25. IN CAL Indicator and RESET Terminal 2-5
2-27. Portability 2-5
2-29. Guarded Operation 2-5
2-33. Oven Temperature Thermistor 2-6
2-36. Minimizing Error Sources 2-6
2-
45. OPERATION 2-7
3THEORY OF OPERATION 3-1
3-
1INTRODUCTION 3-1
3-3. OVERALL FUNCTIONAL DESCRIPTION 3-1
3-8. CIRCUIT DESCRIPTION 3-1
3-10. Power Supply (A3 and A4) 3-1
3-14. Voltage Monitor 3-1
3-17. Reference Circuit, A5 3-2
3-20. Output Divider 3-2
3-22. Oven Controller .3-2
3-
25. Battery Charger 3-2
4MAINTENANCE 4-1
4-
1. INTRODUCTION 4-1
4-5. SERVICE INFORMATION 4-1
4-8. GENERAL MAINTENANCE 4-1
(continued on page it)

732A
TABLE OF CONTENTS, continued
SECTION TITLE PAGE
4-9. Access Procedure 4-i
4-19. Oven Disassembly ;.4-6
4-21. Front Panel Removal 4-6
4-23. Cleaning 4-6
4-26. Fuse Replacement 4-6
4-28. AC Line Voltage Change 4-6
4-30. ACCEPTANCE TEST 4-8
4-32. CALIBRATION 4-8
4-35. Null Verification 4-8
4-37. Procedure A; Calibrate to Certified 732A 4-9
4-39. Procedure B: Calibration to Standard Cells 4-10
4-41, SERVICE/ REPAIR PROCEDURES 4-14
4-42. Introduction 4-14
4-44. Battery Charger Adjustment Procedure 4-14
4-46. TROUBLESHOOTING 4-14
4-47. Introduction 4-14
4-49. External Symptom Troubleshooting 4-16
4-51. Internal Voltage Measurements 4-16
4-53. Oven Repair 4-16
5LIST OF REPLACEABLE PARTS 5-1
TABLE OF CONTENTS 5-1
6ACCESSORIES 6-1
INTRODUCTION 6-1
6-3. DUAL MOUNTING FASTENERS (MOO-800-5237) 6-1
6-5. HALF-WIDTH RACK MOUNT KIT (M07-203-601) 6-1
6-7. FULL-WIDTH RACK MOUNT KIT (M07-200-603) 6-1
6-9. LOW THERMAL EMF CABLE ASSEMBLY (5440A-7002) 6-1
6-11. BATTERY PACK (732A-7001) 6-1
6-13. TRANSIT CASE (732A-7002) 6-1
7GENERAL INFORMATION M
7A MANUAL CHANGE INFORMATION 7A-1
8SCHEMATIC DIAGRAMS 8-1
TABLE OF CONTENTS 8-1
INDEX 8-12
//

List of Tables
TABLE TITLE PAGE
i-I. 732A Accessories ]»}
1-
2, 732A Specificiations U2
2-
1, Front Panel Features 2-4
2-2. Rear Panel Features 2-4
4-1. Test Equipment Required 4-2
4-2. External System Troubleshooting 4-17
4-3, Internal Measurements *4-18

List of Illustrations
FIGURE TITLE PAGE
Frontispiece 732A DC Reference Standard vi
1-
1. 732A Outside Dimensions 1-4
2-
1. Front Panel Features 2-2
2-2. Rear Panel Features 2-3
2-3. Guard Connections 2-6
2-
4. 732A/ Precision Divider, Providing AStable, Adjustable Source 2-8
3-
1. Functional Block Diagram 3-3
4-
1. Cover and Front Panel Screw Locations 4-3
4-2. Rear Module Mounting Screw Locations 4-3
4-3. Regulator PCB Assembly Removal 4-4
4-4. Oven Assembly Removal 4-5
4-5. AC Line Voltage Conversion on A3 Pre-Regulator PCB Assembly 4-7
4-6. 732A lOV Calibration 4-16
4-7. Calibration of Point Ato lOV Using 732A 4-10
4-8. Calibration of 1.081V (and IV) to 732A 4-10
4-9. 732A lOV Calibration Using Standard Cells 4-12
4-10. 732AProcedure ‘B’ lOV Calibration 4-13
4-1 1. Calibration of 1.081V (and IV) to 732A Procedure ‘B’ 4-13
4-12. Battery Charger Test Points and Adjustments on
A3 Pre-Regulator PCB Assembly 4-15

732A DC Reference Standard

732A
Section 1
Introduction and Specifications
1-1. INTRODUCTION
1-2. The Fluke Model 732A is ahighly stable, rugged,
and transportable, solid stale, dc voltage reference
standard. The 732A has lOV, 1.018V and IV outputs.
These outputs are available on front panel binding posts.
The calibration adjustments for the lOV, L018V and IV
outputs are accessible through the front panel. Anon-
conducting adjustment tool is supplied with the unit for
this purpose.
1-3 .All outputs of the 732Acan be shorted indefinitely
without damage. Recovery occurs in less than 2minutes
after the short is removed, with no loss of stability.
I“4. The stability and accuracy of the 732A allow direct
substitution for saturated standard cells in many
applications. The stability specification of 0.5 ppm for 30
days is achieved by enclosing the reference amplifier and
output divider of the 732A in ahigh thermal gain oven.
Full accuracy is attained over the specified ambient
temperature range of 23 ±5^C (64.4 to 82.4"^ F).
Variations in oven temperature may be monitored
externally via the OVEN TEMP THERMISTOR
terminals on the front panel.
I“5. The 732 Amay be powered from ac line power, an
internal rechargeable battery, or an external low voltage
ac or dc source. The 732A is designed to be powered
continuously, including during storage or shipment. The
back-up battery will continue to operate the 732A for up
to 12 hours. Either line or battery power may be removed
without affecting the output. The battery is kept charged
by an internal battery charger when operating from ac
line power, or from the external low' voltage ac or dc
source.
1«6, Various front panel LEDs (indicators) provide a
continuous indication of the operating status of the 732A.
The AC PWR indicator illuminates in the presence of ac
line power. The BTRY CHG indicator is on steadily for
normal charging activity, and is off when the battery is
charged. The IN CAL indicator monitors the input
voltage to the Reference and Oven. Should this voltage
fall below that needed to keep the 732A operational, the
IN CAL indicator is latched off, indicating aloss of power
and standardization. Once power is restored and
standardization has been verified, the IN CAL indicator
can be reset.
1-7. The 732A may be used on the bench or rack
mounted. The 732A is ahalf-rack width instrument and
occupies 4standard 1.75 inch rack spaces. Accessories for
the 732A are listed in Table 1-1 and described in more
detail in Section 6of this manual There are no options
available for the 732A.
1-8* SPECIFICATIONS
I-9. Table I-2 lists the specifications for the 732A.
Table 1-1. Accessories
MODEL
NUMBER DESCRIPTION
MOO-800-523
M07-203-601
M07-200-601
5440A-7002
732A-7001
732A-7002
732A-7003
Dual Mounting Fastener
Half Width Rack Mount Kit
Full Width Rack Mount Kit
Low Thermal EMF Cable Assembly
Battery Pack
Transit Case
Battery Charger
1-1

732A
Table 1-2. 732A Specifications
OUTPUT VOLTAGE 10 volts. 1.018 volts, or 1volt
TRANSFER UNCERTAINTY @18“C to 28°C
Output Voltage Time Interval
30 Days 90 Days 6Months 1Year
10V 0.5 ppm 1.5 ppm 3.0 ppm 6.0 ppm
1.018V 1,5 ppm 4.0 ppm 8.0 ppm 12.0 ppm
1V 1.5 ppm 4.0 ppm 8.0 ppm 12.0 ppm
These specifications assume the unit has been continuously powered up with either ac or battery or both. The
specifications include effects due to line regulation.
TEMPERATURE COEFFICIENT OF OUTPUT
Range Temperature Coefficient (ppm/^C)
OX to 18X 28°C to AO^C
10V ±0.05 ±0.05
1.018V ±1.0 ±1.0
1V ±1,0 ±1.0
OUTPUT ADJUSTMENT AND RESOLUTION
Output Adj. Range AdJ. Resolution
10V ±50a/V <0.05 ppm
1.018V ±50 //V <0.25 ppm
1.0V ±5 /iV <0.10 ppm
OUTPUT IMPEDANCE
10V <5 milliohms
1.018V, IV «1 kilohm
OUTPUT CURRENT
10V 12 mA maximum
1.018V, IV Current limited by Ik Osource impedance
OUTPUT PROTECTION The output may be shorted indefinitely without damage to the
instrument. The instrument is protected against high voltage up to
1000V provided that the net current into the 732A does not exceed
30 mA.
OUTPUT NOISE ^1 A<V RMS at 10V output, 0.1-10 Hz.
LOAD REGULATION AT
0.12 mA OUTPUT CURRENT <6.0 ppm
LINE REGULATION <0.05 ppm of output for full ±10% power line variation.
LINE POWER REQUIREMENTS
Nominal Setting Voltage Limits Fuse
100V 90- 110V 0.375A/250V SLO-BLO
120V 108- 132V 0.375A/250V SLO-BLO
220V 198-242
V
0.250A/250V slO-BLO
240V 216-264V 0.250A/250V SLO-BLO
1-2

732A
1*2. 732A Specifications (cont)
Condition Temperature o/o Relative Humidity
(»C) (Non-condensing)
Non-operating -40 to +50 Not Controlled
Oto 50 95 ±5%
Operating Oto 30 95 ±5%
30 to 40 7±5%
VIBRATION
Frequency GForce Frequency Double AmpHlude
5-55 Hz 2@55 Hz 0.013 inch
1-3

732A
V4