Keithley 6521, Instruction Manual, Page: 13 / 65

List of Illustrations
2 Card Connections and Installation
Figure 2-1 Model 6521 simplified schematic ............................................................................................................... 2-2
Figure 2-2 Model 6521 connecting cables.................................................................................................................... 2-2
Figure 2-3 Model 6522 simplified schematic ............................................................................................................... 2-2
Figure 2-4 Model 6522 connecting cables.................................................................................................................... 2-3
Figure 2-5 Typical amps function connections............................................................................................................. 2-3
Figure 2-6 Typical volts function connections ............................................................................................................. 2-3
Figure 2-7 Typical ohms function connections ............................................................................................................ 2-4
Figure 2-8 Typical coulombs function connections ..................................................................................................... 2-4
Figure 2-9 Typical guarded volts connections (Model 6522 only)............................................................................... 2-5
Figure 2-10 Scanner card installation ............................................................................................................................. 2-6
Figure 2-11 Output connections ..................................................................................................................................... 2-7
3 Operation
Figure 3-1 Path isolation resistance .............................................................................................................................. 3-8
Figure 3-2 Voltage attenuation by path isolation resistance......................................................................................... 3-9
Figure 3-3 Power line ground loops ............................................................................................................................. 3-9
Figure 3-4 Eliminating ground loops.......................................................................................................................... 3-10
Figure 3-5 Guarded operation..................................................................................................................................... 3-10
Figure 3-6 Capacitor leakage test system ................................................................................................................... 3-11
Figure 3-7 High-resistance test system....................................................................................................................... 3-12
Figure 3-8 Low-current test system ............................................................................................................................ 3-13
4 Service Information
Figure 4-1 Connections for offset current verification ................................................................................................. 4-3
Figure 4-2 Connections for signal path contact resistance tests ................................................................................... 4-4
Figure 4-3 Connections for ground relay contact resistance tests ................................................................................ 4-5
Figure 4-4 Connections for channel isolation............................................................................................................... 4-7
Figure 4-5 Connections for input isolation ................................................................................................................... 4-7
Figure 4-6 Block diagram ............................................................................................................................................. 4-8
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