Keithley 3720 User Manual page 16

List of Figures
Figure 5-9: Two-wire switching module resistance connection ............................................. 5-19
Figure 5-10: Four-wire switching module resistance connection ........................................... 5-19
Figure 5-11: Enabling offset-compensated ohms ................................................................. 5-21
Figure 5-12: Four-wire Ohm ATTR MENU: OFFSETCOMP ................................................. 5-22
Figure 5-13: Enabling dry-circuit ohms ................................................................................ 5-24
Figure 5-14: Four-wire Ohm ATTR MENU: DRYCIRCUIT .................................................... 5-24
Figure 5-15: Two-wire constant-current source method ....................................................... 5-27
Figure 5-16: Four-wire constant-current source method ....................................................... 5-27
Figure 5-17: Two-wire ratiometric method............................................................................ 5-28
Figure 5-18: Four-wire ratiometric method ........................................................................... 5-29
Figure 5-19: Simplified Dry-Circuit open lead detection schematic ....................................... 5-30
Figure 5-20: Simplified normal four-wire open lead detection schematic .............................. 5-31
Figure 5-21: Simplified Dry-Circuit open V-clamp feedback loop schematic ......................... 5-34
Figure 5-22: Simplified T/C open lead detection schematic .................................................. 5-38
Figure 5-23: Simulated reference junction ........................................................................... 5-40
Figure 5-24: Simulated reference junction switching module ................................................ 5-40
Figure 5-25: Internal reference junction (40 channel switching module) ............................... 5-40
Figure 5-26: Thermistor analog backplane connection ......................................................... 5-42
Figure 5-27: Thermistor switching module connection ......................................................... 5-42
Figure 5-28: Three-wire RTD connections ........................................................................... 5-44
Figure 5-29: Three-wire RTD switching module connections ................................................ 5-44
Figure 5-30: Four-wire RTD connections ............................................................................. 5-45
Figure 5-31: Four-wire RTD switching module connections.................................................. 5-45
Figure 5-32: FREQ and PERIOD input connections ............................................................. 5-49
Figure 5-33: FREQ and PERIOD connections (switching module) ....................................... 5-49
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System Switch/Multimeter User's Manual
Document Number: 3700S-900-01 Rev. A / August 2007