Fluke 1625 User Manual

Stakeless Earth/Ground Resistance Testing
Principle of Operation
67
If the parallel connection of resistors, R1...Rn is considerably lower than the
ground connection under test R
X
:
R
RRR
X
n
<<
⋅⋅⋅⋅++
111
1
21
then
I
U
R
X
= is a reasonable approximation.
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.
R
X
R
1
R
2
R
n-1
R
n
Current
I
Voltage
U
edw062.eps
After synchronous rectification of current and voltage the tester displays R
X
.

Fluke 1625 Specifications

General

Storage Temperature	-20 °C to 60 °C
Testing Methods	3-pole fall-of-potential, 4-pole
Measurement Frequency	128 Hz
Power Supply	6 x 1.5 V AA batteries or optional AC adapter
Safety Rating	CAT II 300 V
Safety Standards	IEC 61010-1