Fluke 792A Autre
Fabricant:
Modèle:
792A
Date:
1992
Catégorie:
Groupe:
Description:
AC/DC Transfer Standard

Information

The 792A AC/DC Transfer Standard is a laboratory standard instrument that calibrates ac voltage calibrators, ac/dc transfer standards, and ac voltmeters. It consists of four main components: a transfer standard sensor unit (called the transfer standard in this manual), power pack, 1000V range resistor, and transfer switch. Inputs are accepted in the range 2 mV to 1000V rms, 10 Hz up to 1 MHz, with a maximum Volt-Hertz product of 10 The 792A compares the heating effect of an ac voltage with that of a known dc voltage (or other ac voltage). Sensing the rms value is done entirely without thermocouples and the drawbacks that accompany them. (See The Fluke RMS Sensor, paragraph 1-3, for more information.) The transfer standard accepts dc and ac voltages through a stainless steel Type “N” INPUT connector and presents a dc voltage at the front panel DC OUTPUT binding posts that is linearly proportional to the rms potential of the input. A digital voltmeter of 6V4-digit resolution or better can be used to resolve the 2.0V nominal full-scale output. An OVERLOAD indicator and beeper warns of input overloads. Even though the transfer standard is protected electronically from overloads, it is a delicate laboratory instrument and should be treated with extreme care. Before operating the transfer standard, be sure to read Sections 2 and 3, particularly the WARNING that explains the restriction to use only sources that are current-limited to 200 mA or less (at the beginning of Section 2), and the CAUTION about observing the voltage protection level limits for each INPUT RANGE setting.

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Service et Manuel de l'utilisateur
Type manuel:
Service et Manuel de l'utilisateur
Pages:
192
Taille:
14.92 Mbytes (15648385 Bytes)
Langue:
english
Révision:
1
Manuel-ID:
871723
Date:
1992 12 01
Qualité:
Document scanné, tous les lisible.
Date de transfert:
2017 02 04
MD5:
b477ec8f6ddf02b1c744c01150727dca
Téléchargements:
939

Information

1 INTRODUCTION AND SPECIFICATIONS ... 1-1 1-1. INTRODUCTION ... 1-1 1-2. THE Fluke RMS SENSOR ... 1-1 1-3. STANDARD EQUIPMENT ... 1-2 1-4. 792A AC/DC Transfer Standard ... 1-2 1-5. 792A-7001 Power Pack ... 1-2 1-6. 792A-7002 1000V Range Resistor ... 1-2 1-7. 792A-7003 Transfer Switch ... 1-2 1-8. Stainless Steel Type “N” Extender ... 1-3 1-9. Power Pack Cable ... 1-3 1-10. ACCESSORY Fluke A40 CURRENT SHUNT ADAPTER ... 1-3 1-11. SERVICE AND CALIBRATION INFORMATION ... 1-3 1-12. SPECIFICATIONS ... 1-4 2 INSTALLATION AND SAFETY ... 2-1 2-1. INTRODUCTION ... 2-1 2-2. UNPACKING AND INSPECTION ... 2-2 2-3. ENVIRONMENTAL AND INPUT REQUIREMENTS ... 2-3 2-4. SELECTING LINE VOLTAGE AND ACCESSING THE FUSE ... 2-4 2-5. CONNECTING TO LINE POWER ... 2-5 3 OPERATION ... 3-1 3-1. INTRODUCTION ... 3-1 3-2. SUMMARY OF FEATURES ... 3-1 3-3. 792A AC/DC Transfer Standard Front Panel ... 3-1 3-4. 792A AC/DC Transfer Standard Rear Panel ... 3-1 3-5. 792A-7001 Power Pack Front Panel ... 3-1 3-6. 792A-7001 Power Pack Rear Panel ... 3-2 3-7. 792A-7002 1000V Range Resistor ... 3-2 3-8. 792A-7003 Transfer Switch ... 3-2 3-9. 792A Test Report ... 3-2 3-10. USING THE POWER PACK ... 3-14 3-11. PREPARING TO MAKE A TRANSFER ... 3-15 3-12. Using the 792A Test Report ... 3-15 3-13. Using the Fluke 5700A with the Transfer Standard ... 3-16 3-14. Initial Setup and Warmup 3-16 3-15. Cable Connections for Making a Transfer ... 3-17 3-16. Connecting and Using the Transfer Switch ... 3-17 3-18. Connecting DC Voltage Sources to the INPUT ... 3-18 3-19. Connecting AC Voltage Sources to the INPUT ... 3-18 3-20. When to Use Four-Wire Sensing 3-19 3-21. Connecting the Guard and Ground ... 3-19 3-22. MAKING A TRANSFER 3-20 3-23. Using a Deflection Method to Measure an AC Voltage Source .. 3-21 3-24. Using a Nulling Method to Measure an AC Voltage Source ... 3-24 3-25. Determining the Error of an AC Voltmeter ... 3-25 3-26. Calibrating Another Transfer Standard ... 3-30 3-27. TECHNIQUES FOR REDUCING TRANSFER ERRORS ... 3-30 3-28. DC Reversal 3-30 3-29. Loading 3-31 3-30. Mechanical Contact 3-31 3-31. Thermal EMFs 3-32 3-32. EMI ... 3-32 4 THEORY OF OPERATION ... 4-1 4-1. INTRODUCTION ... 4-1 4-2. OVERALL FUNCTIONAL DESCRIPTION ... 4-1 4-3. Range Resistors and Amplifiers 4-2 4-4. RMS Sensing and Sensor Protection ... 4-2 4-5. Output Filter/Buffer 4-2 4-6. Binding Posts 4-2 4-7. 792A-7001 Power Pack 4-2 4-7. DETAILED CIRCUIT DESCRIPTION ... 4-2 4-8. Fluke RMS Sensor Circuit 4-2 4-9. Passive (Non-Amplified) Ranges 4-3 4-10. 792A-7002 1000V Range Resistor 4-3 4-11. Active (Amplified) Ranges 4-3 4-12. Sensor Protection Circuit 4-4 4-13. Power Pack 4-5 4-14. Overcurrent Protection 4-5 4-15. Battery Voltage Monitor 4-5 4-16. On/Off Circuit 4-5 4-17. Relays ... 4-5 5 MAINTENANCE ... 5-1 5-1. INTRODUCTION ... 5-1 5-2. REPLACING THE FUSE 5-1 5-3. GENERAL CLEANING 5-1 5-4. CALIBRATION 5-1 5-5. PERFORMANCE TESTING 5-6 5-6. Testing the Power Pack 5-7 5-7. Testing the Power Pack Interconnect Cable ... 5-7 5-8. Testing the Transfer Switch 5-7 5-9. Testing the Sensor Unit and 1000V Range Resistor ... 5-9 5-10. ACCESS PROCEDURES ... 5-9 5-11. Power Pack Initial Access Procedure ... 5-10 5-12. ACCESSING THE A3 Power supply PCA ... 5-10 5-13. REPLACING THE BATTERIES ... 5-10 5-14. Sensor Unit Initial Access Procedure ... 5-12 5-15. REPLACING THE Fluke RMS SENSOR (U111) ... 5-12 5-16. ACCESSING THE Filter PCA ... 5-14 5-17. TUNING THE SENSOR UNIT ... 5-14 5-18. TROUBLESHOOTING ... 5-20 5-19. Troubleshooting the Power Pack ... 5-21 5-20. Troubleshooting the Sensor Unit ... 5-21 5-21. PROTECTION CIRCUIT ... 5-23 5-22. OUTPUT CIRCUIT ... 5-23 5-23. CLEANING PCA’S ... 5-25 5-24. LUBRICATING THE TRANSFER SWITCH ... 5-25 6 LIST OF REPLACEABLE PARTS ... 6-1 CONTENTS ... 6-1 6-1. INTRODUCTION ... 6-3 6-2. HOW TO OBTAIN PARTS ... 6-3 6-3. MANUAL STATUS INFORMATION ... 6-3 7 SCHEMATIC DIAGRAMS ... 7-1 CONTENTS ... 7-1 APPENDICES APPENDIX A GLOSSARY ... A-l APPENDIX B USING THE 792A-7004 A40 CURRENT SHUNT ADAPTER B-l APPENDIX C CALCULATING CORRECTION FACTORS FOR FC100 HZ C-l APPENDIX D ESTABLISHING TRACEABILITY FOR A HIGH PERFORMANCE AC/DC TRANSFER STANDARD ... D-l APPENDIX E USING A LINEAR Thermal Transfer Standard FOR PRECISION AV/DV TRANSFERS ... E-l INDEX

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