GRT300-EU-EN v1.1 08/13
5
Earth Resistance measurement
Note: The measured results may be influenced by inductive or capacitive coupling if the test leads
are twisted or adjacent to each other. When connecting the Probes, keep the leads separated.
Setup
Insert the Potential spike and the Current spike (if required) as deep as possible into the soil. The
distance between spikes must be 5 to 10 meters (16 to 32 feet).
Four-terminal earth resistance measurements
1
2
MAX.
AC 300V
H
S
E
ES
P
2
C
2
C
1
P
1
3
(1) Earth electrode (rod) under test (2) Potential spike (3) Current spike
Three-terminal earth resistance measurements
1
2
MAX.
AC 300V
H
S
E
ES
P
2
C
2
C
1
P
1
3
(1) Earth electrode (rod) under test (2) Potential spike (3) Current spike
Two-terminal earth resistance measurements
1
2
MAX.
AC 300V
P
2
C
2
C
1
P
1
H
S
E
ES
(1) Earth electrode (rod) under test (2) Potential spike
