Hewlett Packard 428B Analog multimeter
Manufacturer:
Model:
428B
Date:
1962
Class:
Type:
SubType:
Clip-On Milliammeter
Information
The Model
428B Clip-On Milliammeter measures the magnetic field, which exists around the wire carrying dc current. Operating the instrument Is simple. After zero setting, the two jaws of the
Probe are clamped around wire (arrow on
Probe head indicates direction of conventional current flow) and the meter will indicate the current.
There are nine current ranges starting from 1 ma to 10 amp full scale deflection. The sensitivity can be increased even further by looping the wire several times through the opening in the
Probe. The current indication is virtually insensitive to super* imposed ac signals and the series loading of the circuit is less than 0.5 µh. A large amount of feedback provides great stability. With the Mode]
428B currents can be measured as easily as measuring voltages with a voltmeter.
Manual type:
Service and User Manual
Pages:
50
Size:
15.03 Mbytes (15758016 Bytes)
Language:
english
Revision:
Manual-ID:
00428-90002 and/or 01171-4
Date:
1966 10 01
Quality:
Scanned document, reading partly badly, partly not readable.
Upload date:
2020 05 31
MD5:
3d0b65143cc85f5f1c599452199040ca
Downloads:
306
Information
Serial Prefixed: 131-, 601-
Section Page
I GENERAL ... 1-1
1-1. Introduction ... 1-1
1-4. Other
Probe Heads ... 1-1
1-7. Instrument Identification ... 1-1
n PREPARATION FOR USE ... 2-1
2-1. Unpacking and Mechanical Inspection 2-1
2-4. Operation Check ... 2-1
2-6. Installation ... 2-1
2-8. Power Requirements ... 2-1
2-10. Operation on 115 or 230 Volte. . . . 2-1
2-13. Three Conductor Power Cable . . . 2-1
2-15. Rack-Mount Model ... 2-1
2-17. Preparatlonfor Storage and Shipment 2-1
2-20. Storage ... 2-1
m OPERATION ... 3-1
3-1. Turn-On Procedure ... 3-1
3-4. Mechanical Operation of
Probe . . . 3-1
3-6. Electrical Zero Set ... 3-1
3-10. Degaussing of
Probe Head ... 3-1
3-13. Measurement Precautions ... 3-1
3-15. Handling of
Probe ... 3-1
3-21. Magnetic Fields ... 3*28. AC Fields and Superimposed AC 3-2
Current ... 3-2
3-32. Effect of Instrument on Circuit . 3-2
3-35. Effect of Circuit on Instrument . 3-2
3-37. Measurement Practices ... 3-3
3-38. Polarity of Current ... 3-3
3-40. Increasing the Absolute Sensitivity 3-3
3-42. Current Check Loops ... 3-3
3-44. Use of Output Jack ... 3-3
IV THEORY ... 4-1
4-1. Introduction ... 4-1
4-3. Overall Operation ... 4-1
4-9. Current
Probe ... 4-1
4-19. 20 KC
Oscillator ... 4-2
4-23. Head Drive
Amplifier ... 4-2
Section Page
IV THEORY (Cont'd)
4-25. Detector Gate
Amplifier ... 4-2
4-28. 40-KC Input/Amplifier Circuit . . . 4-3
4-30. Synchronous Detector and Filter
(C24) ... 4-3
4-36. DC
Amplifier ... 4-4
4-43. Negative Feedback Current Circuit . 4-4
4-45. 40 KC Phase Shifter ... 4-5
4-48.
Power supply ... 4-5
V MAINTENANCE ... 5-1
5-1
5-7. Mechanical Zero-Set ... 5-1
5-9. Cleaning of
Probe Jaws ... 5-1
5-11. Test Equipment ... 5-1
5-13. Test Instruments ... 5-1
5-14. Auxiliary Equipment ... 5-1
5-15. Adjustment After Tube Replacement 5-5
5-21. Trouble Localization ... 5-5
5-26.
Probe ... 5-5
5-28.
Power supply ... 5-5
5-29. Oscillator-HeadDrive
Amplifier. 5-5
5-30. Head Drive ... 5-6
5-31. Synchronous Detector ... 5-6
5-32. DC
Amplifier ... 5-6
5-33. Adjustment After Current Probe
Replacement ... 5-8
5-35. Complete Adjustment Procedure . . 5-8
5-37. Final Check ... 5-12
5-40. Range Calibration ... 5-12
5-42. Meter Tracking ... 5-13/5-14
5-45. Loop Gain ... 5-13/5-14
VI REPLACEABLE PARTS ... 6-1
6-1. Introduction ... 6-1
6-4. Ordering Information ... 6-1
Appendix
A CODE LIST OF MANUFACTURERS
B SALES AND SERVICE OFFICES
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