Fluke 1625 User Manual page 75

If the parallel connection of resistors, R1...Rn is considerably lower than the
ground connection under test R
1
1 1
R R
1 2
U
R
then is a reasonable approximation.
X
I
The test voltage (U) is applied without disconnecting ground rod and/or the
direct electrical connection by means of a clamp-on current transformer and
the current detected by a second current transformer.
Voltage
U
Current
I
After synchronous rectification of current and voltage the tester displays R
Stakeless Earth/Ground Resistance Testing
:
X
R
1
X
R
n
R R
X 1
Principle of Operation
R R
2
R
n-1 n
edw062.eps
.
X
67