HP 412A User Manual

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Model 4 12A
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TABLE OF CONTENTS
Section Page
I GENERAL INFORMATION ................. 1-1
1.1 . Introduction ......................... 1-1
1.7 .
Specifications ........................ I -I
1.Y . instrument and Manual Identification ..... 1-1
. Section
I . ?
Page
11 INSTALLATlON .......................... 2-1
2.1
. Introduction ......................... 2-1
2.3
. Initial inspection ..................... 2-1
2.5 . Power Requirements ................... 2-1
2.7 . Grounding Requirements ............... 2-1
2.10 . lnstallatiori .......................... 2-1
2.13
. Repackaging for Shipment .............. 2-1
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1 Section Page
I11 OPERATING INSTRUCTIONS ............... 3-1
3.1
. Introduction ......................... 3-1
3.3 . Low-Level Electrical Phenomena ......... 3-1
3.7 . Turn& Procedure .................... 3-1
3-8 . Voltage Measurement .................. 3-1
3.9 . Current Measurement .................. 3-1
3-1 0 . Resistance Measurement ................ 3-2
3-1 2
. Amplifier Operation ................... 3-3
Y
Section Page
Table
of Contents
List
of Tables
Section page
5.1 . lntroduction ......................... 5-1
5.3 . Required Test Equipment ............... 5-1
5.5 . Performance Checks ................... 5-1
5.7 . Meter Zero ......................... 5-1
5.10 . Voltmeter Accuracy Check ............. 5-1
5-1 1 . Milliammeter Accuracy Clieck .......... 5-1
5-1 2 . Ohmmeter Accuracy Check ............ 5-2
5.13 . Input Kcsistance Clieck ............... 5-3
5.14 . AC Kejection Check .................. 53
5.15 . Adjustment and Calibration Proccdure ...... 53
5.17 . Cabinet Removal .................... 53
5.18 . Mechanical Adjustment of Meter Zero .... 5-3
5.20 . Hum Balance Adjustment .............. 5-5
5.21 . Cathode Follower Bias Adjustrncnt ...... 5-5
5.22 . Meter Electrical Zero Adjustment ........ 5-5
5.23 .
5.24 .
V MAINTENANCE .......................... 5-1
Amplifier Gain Adjustment and
Meter Calibration
................... 5-5
Olimmeter Adjustment ................ 5-5
5.25 . Troubleshooting ...................... 54
5.27 . Front Panel Indications ............... 54
5.29 . Power Supply and Amplifier Checks ...... 56
5.33 . Modulator Clieck .................... 54
5.34 . Modulator Replacement ............... 5-7
5.36 . Demodulator Check .................. 5-7
5.37 . Demodulator Replacement ............. 54
5.39 . Switch Checks ...................... 5-8
541 . Adjustment of Factory Selcctcd
Components
....................... 54
546 . Input Cable Keplacemcnt .............. 5-0
Section Pap
VI REPLACEABLEPARTS .................... 6-1
IV
THEORY OF OPERATION .................. 4-1
6.1 . lntroduction ......................... 6-1
4.1 . General ............................. 4-1 64 . Ordering Information .................. 6-1
4.3 . Block Diagram Analysis ................ 4-1 6.6. Non-Listed Parts ...................... 6-1
Section l’ilgc
4.9 . Modulator. Amplifier. Demodulator. VI1 CIRCUITDIAGRAMS ...................... 7-1
........... 4.5. Range and Function Selection 4-1
4.7 . Filters .............................. 4-1
and Chopper ........................ 4-1
7.1 . Introduction ......................... 7-1
4-1 1 . Cathode Follower and Polarity Selection ... 4-1
LIST OF TABLES
Page Number Pagc
Number
1.1
. Specifications ............................. 1.0
3.1 . Voltage and Current in Resistance
Measurements
............................ 3-2
5.1 . Test Equipment Required .................... 54
5.2 . Millianimeter Accuracy Check ................ 5-2
5.3 . Input Resistance Chccks ..................... 5-3
5.5 . Tubc Replacement ......................... 541
6-1 . Rcplaccablc Parts .......................... 6-2
54 . Power Supply Voltages ..................... :54
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HP 412A Specifications

General

Brand	HP
Model	412A
Category	Measuring Instruments
Language	English