z
4-Terminal (4T)
4-Terminal connection reduces the effect of the test lead
resistance (Figure 3.3). This connection can improve the
measurement range down to 10m
Ω
. However, the effect of the
test lead inductance can’t be eliminated.
H
CUR
H
POT
DUT
(b) BLOCK DIAGRAM
DUT
V
A
(a) CONNECTION
(c) TYPICAL MPEDANCE MEASUREMENT RANGE (£[)
4T
1m 10m 100m 1
10
1K 10K 100K 1M
100
10M
L
POT
L
CUR
Figure 3.3
z
5-Terminal (5T)
5-Terminal connection is the combination of 3T and 4T (Figure
3.4). It has four coaxial cables. Due to the advantage of the 3T
and 4T, this connection can widely increase the measurement
range for 10m
Ω
to 10M
Ω
.
42