Specifications

3.1.4 Five-terminal configuration
The five-terminal (5T) configuration is a combination of the three-terminal (3T) and four-terminal
(4T) configurations. It is equipped with four coaxial cables and all of the outer shielding conductors
of the four cables are connected to the guard terminal (see Figures 3-6 (a) and (b).) This configura-
tion has a wide measurement range from 10 mΩ to 10 MΩ, but the mutual coupling problem still
remains. If the outer conductors are connected to each other at the ends of the cables, as shown in
Figure 3-7, the accuracy for the lower impedance measurement is improved a little. This configuration
is called the shielded 4T configuration.
Figure 3-6. Five-terminal (5T) configuration
Figure 3-7. Shielded four-terminal (4T) configuration
(a) Schematic diagram
DUT
V
Null
detector
H
p
H
c
L
c
L
p
R
s
R
r
(b) Connection image
Connect here
H
p
H
c
L
c
L
p
Connect here
(a) Schematic diagram
DUT
V
Null
detector
H
p
H
c
L
c
L
p
R
s
R
r
(b) Connection image
H
p
H
c
L
c
L
p
(d) Typical impedance
measurement range
(c) Residual parameters
H
p
H
c
L
c
L
p
DUT
R
L
L
L
M
M
1 m 10 m 100 m 1 10 100 1 K 10 K 100 K 1 M 10 M (Ω)
3-5