Keithley 2657A

Model 2657A High Power System SourceMeter® Instrument Reference Manual Section 2: General operation
2657A-901-01 Rev. B/December 2012 2-33
Figure 8: Two-wire resistance sensing
I
HI
V
M
V
R
Test Current (I)
Resistance
Under Test
Lead
Resistances
R
S
I = Current sourced
V
M
= Voltage measured
V
R
= Voltage across resistor
LO
R
LEAD
R
LEAD
=
R
S
+ (2 × R
LEAD
)
V
M
Measured resistance =
V
M
I
=
R
S
Actual resistance =
V
R
I
Model 2657A
L
ea
d
R
es
i
st
a
n
ces
R
LEAD
R
LEAD