Fluke 8842A User Manual

Contents (continued)
iii
3-50. The Serial Poll Register ................................................................... 3-27
3-51. The SRQ Mask................................................................................. 3-28
3-52. INTERFACE MESSAGES .................................................................. 3-29
3-53. Address Messages............................................................................ 3-29
3-54. Universal Commands....................................................................... 3-29
3-55. Addressed Commands...................................................................... 3-30
3-56. TALK-ONLY MODE .......................................................................... 3-30
3-57. REMOTE CALIBRATION.................................................................. 3-31
3-58. TIMING CONSIDERATIONS............................................................ 3-31
3-59. IMMEDIATE MODE COMMANDS.................................................. 3-31
3-60. EXAMPLE PROGRAMS .................................................................... 3-32
4 Measurement Tutorial........................................................................ 4-1
4-1. INTRODUCTION................................................................................ 4-2
4-2. DC VOLTAGE MEASUREMENT ..................................................... 4-2
4-3. Circuit Loading Error....................................................................... 4-2
4-4. Input Bias Current Error................................................................... 4-3
4-5. RESISTANCE MEASUREMENT ...................................................... 4-4
4-6. 2-Wire Ohms.................................................................................... 4-4
4-7. Correcting for Test Lead Resistance in 2-Wire Ohms..................... 4-5
4-8. 4-Wire Ohms.................................................................................... 4-5
4-9. Applications of the Ohms Functions................................................ 4-7
4-10. TESTING DIODES..................................................................... 4-7
4-11. TESTING ELECTROLYTIC CAPACITORS ............................ 4-7
4-12. A PRECISION CURRENT SOURCE......................................... 4-8
4-13. DC CURRENT MEASUREMENT ..................................................... 4-8
4-14. REDUCING THERMAL VOLTAGES............................................... 4-9
4-15. AC VOLTAGE AND CURRENT MEASUREMENT........................ 4-10
4-16. True RMS Measurement.................................................................. 4-10
4-17. Waveform Comparison.................................................................... 4-10
4-18. Crest Factor...................................................................................... 4-12
4-19. AC-Coupled AC Measurements ...................................................... 4-12
4-20. Combined AC and DC Measurements............................................. 4-13
4-21. Bandwidth........................................................................................ 4-13
4-22. Zero-Input VAC Error...................................................................... 4-13
4-23. MAKING ACCURATE MEASUREMENTS ON THE 20 mV
AND 20Ω RANGES ............................................................................ 4-14
4-24. MAKING ACCURATE HIGH-RESISTANCE MEASUREMENTS. 4-15
5 Theory of Operation........................................................................... 5-1
5-1. INTRODUCTION................................................................................ 5-3
5-2. OVERALL FUNCTIONAL DESCRIPTION...................................... 5-3
5-3. DETAILED CIRCUIT DESCRIPTION .............................................. 5-4
5-4. DC SCALING...................................................................................... 5-4
5-5. VDC Scaling.................................................................................... 5-6
5-6. VDC Protection................................................................................ 5-7
5-7. mA DC Scaling................................................................................ 5-7
5-8. Analog Filter .................................................................................... 5-7
5-9. TRACK/HOLD CIRCUIT ................................................................... 5-8
5-10. Track Configuration......................................................................... 5-10
5-11. Settling Configuration...................................................................... 5-11
5-12. Hold Configuration .......................................................................... 5-11
5-13. Pre-Charge Configuration................................................................ 5-11
5-14. PRECISION VOLTAGE REFERENCE.............................................. 5-11

Fluke 8842A Specifications

General

Maximum Voltage	1000 V
Maximum Current	2 A
Operating Temperature	0°C to 50°C
Weight	2.5 kg
DC Voltage Range	100mV to 1000V
DC Current Range	0 to 2 A
AC Current Range	0 to 2 A
Frequency Range	20 Hz to 20kHz
Basic Resistance Accuracy	0.01%
Dimensions	216mm x 88mm x 280mm
Resistance Range	200 Ω to 20 MΩ