Keithley 2000-SCAN-20 Instruction Manual page 45

3-10 Operation
4-wire resistance tests
More precise measurements over a wider range of system and DUT conditions can be
obtained using the 4-wire measurement scheme shown in
from the Model 2000-20 Multimeter are routed through the scanner to the resistor under test.
The extra set of sense leads minimizes the effects of voltage drops across the test leads, greatly
reducing measurement errors with lower DUT resistances. Note, however, that an extra two
poles of switching are required for each resistor tested. For this reason, only ten resistors can be
tested using this configuration.
Figure 3-2
4-wire resistance test connections
DMM 2000-20
Rear Panel
2000-SCAN-20
Out A
HI
10
LO
Sense HI
Sense LO
Out B
A. Test Configuration
HI
Sense HI
LO
Ω
Sense LO
2000-20
2000-SCAN-20
B. Simplified Equivalent Circuit
Figure 3-2. Here, separate sense leads
1
DUTs
1
(10)
10
11
20
R
DUT