Floating The Model 2461 - Keithley 2461 Reference Manual

Model 2461 Interactive SourceMeter® Instrument Reference Manual

Floating the Model 2461

INPUT/OUTPUT LO is not internally connected to the chassis and cannot be allowed to float
above chassis ground more than the values shown on the front panel.
If you use an external source in the test system, you may need the Model 2461 to float off chassis
earth ground. An example is shown below, which includes an external voltage source. Notice that
output LO of the external voltage source is connected to chassis ground.
For the test circuit shown below, the Model 2461 must float off chassis ground. As shown, LO of the
Model 2461 is floating +10 V above chassis earth ground. If LO of the Model 2461 was instead
connected to chassis ground, the external voltage source would be shorted to the chassis ground.
2461-901-01 A/November 2015
Figure 153: Floating the instrument schematic
Section 4: Source-measure considerations
4-13