Keithley 6221 User Manual

2-16 Output Connections Model 6220/6221 Reference Manual
Return to Section 2 topics
Figure 2-11
Basic connections to DUT
Shields and guarding
Noise shield connections
Figure 2-12 shows typical noise shielding for the two triax connector
configurations. A noise shield is used to prevent unwanted signals from being
induced into the test circuit. A test current below 1μA may benefit from effective
shielding. Typically, the metal noise shield surrounds the DUT and is connected to
Output Low.
Safety shield connections
A safety shield must be used whenever hazardous voltages (>30Vrms, 42Vpeak)
will be present. The metal safety shield must completely surround DUT test
circuitry and must be connected to a known Safety Earth Ground and Chassis
(see Figure 2-13). Use #18AWG wire or larger for connection to safety Earth
Ground and Chassis.
High
Low
DUT
Output
High
Low
DUT
Output
622x
A) Inner shield connected to Output Low
622x
B) Inner shield connected to Cable Guard
(red*)
* Boot color for alligator clip if
using supplied triax cable.
(red*)
(black*)
(green*)
(Earth Ground)
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Keithley 6221 Specifications

General

Interface	GPIB, RS-232
Communication Interface	GPIB, RS-232
Current Sourcing Accuracy	±(0.03% of output + 20 pA)
Current Sinking Accuracy	±(0.03% of output + 20 pA)
Output Resolution	100 fA
Output Accuracy	±(0.03% of output + 20 pA)
Power Requirements	100 V to 240 V AC, 50/60 Hz