Chapter
II
48
Digital
Earth
Tester
TYPICAL INFLUENCE OF PARASITE VOLTAGE IN EARTH MEASUREMENTS
20 Ohm Range
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0
5
10
15
20
Parasite voltage (V) 16 2/3 Hz to 60 Hz
M
eas
u
rem
en
t er
ro
r %
Ra = 1 Ohm
Ra = 10 Ohm
2000 Ohm Range
0
1
2
3
4
5
6
7
8
0
5
10
15
20
Parasite voltage (V) 16 2/3 Hz to 60 Hz
M
eas
u
rem
en
t e
rr
o
r %
Ra = 10 Ohm
Ra = 100 Ohm
from 16 2/3 Hz to 60 Hz
from 16 2/3 Hz to 60 Hz
