40
3-Terminal (3T)
3-Terminal uses coaxial cable to reduce the effect of the
parasitic capacitor (Figure 3.2). The shield of the coaxial cable
should connect to guard of the instrument to increase the
measurement range up to 10M
Ω
.
DUT
V
A
(d) 2T CONNECTION WITH SHILDING
H
CUR
H
POT
DUT
(b) BLOCK DIAGRAM
DUT
V
A
Co
R
o
L
o
R
o
L
o
Co doesn't
effect
measurement
result
(a) CONNECTION
(c) TYPICAL IMPEDANCE MEASUREMENT RANGE(£[)
3T
1m 10m 100m 1
10
1K 10K 100K 1M
100
10M
L
POT
L
CUR
Figure 3.2