Keithley 8010 Reference Manual page 12

To keep users safe, always read and follow all
safety warnings provided with each of the
instruments in your system.
Hazardous voltages may be present on the output and guard
terminals. To prevent electrical shock that could cause injury or
death, NEVER make or break connections to the Model 8010
while the output from the SourceMeter Instrument (SMU) is on.
Turn off the instrument from the instrument front panel or
disconnect the main power cord from the rear of the instrument
before handling cables connected to the outputs. Putting the
SMU into standby does not guarantee the outputs are not
powered if a hardware or software fault occurs.
Verify that all wiring is inside of the cross-hatched area of the
test fixture. Ensure that wires do not protrude beyond the fixture
lid and that the lid will close securely. Exposed wire may result
in electric shock, causing death or serious injury.
The Model 8010 is provided with two protective earth (safety
ground) terminals on the rear panel. Ensure that both protective
earth terminals are properly connected to a known protective
earth before connecting instruments to the test fixture. Failure to
connect both protective earth terminals can result in electric
shock.