Earth/Ground Measurement (4-Pole); Measurement Without A Clamp - AEMC 6472 User Manual

5.5 Earth/Ground Measurement (4-Pole)

5.5.1

Measurement without a Clamp

This function is suited to the measurement of very low earth resistances. It
provides better resolution (10x better than 3P measurement) and there is no need
to compensate for the resistance of the measurement leads.
1. Set the switch to
2. Place electrodes H (Z) and S (Y) at least 30m apart.
In order to avoid electromagnetic interference, it is best to unwind the full length of
each cable from the reel, to keep the cables as far apart as possible on the ground,
taking care not to form loops, and to avoid placing the cables near or parallel to
metallic conductors (cables, rails, fences, etc.). Connect the cables to terminals
H (Z) and S (Y); disconnect the earth strap from the rod under test, then connect
terminals E (X) and ES (Xv) to the earth electrode to be tested.
3. Start the measurement by pressing the START/STOP button.
4. To display the measurement parameters, press DISPLAY several times.
The device displays the following parameters:
R , U , I , U-Act (U
E S-E H-E
To measure the resistances of auxiliary electrodes H (Z) and S (Y), or if the resis-
tance of the electrodes is too large (see § 10.1), start the measurement with a long
press of the START/STOP button.
R , R , U will be displayed.
H S H-E
Ground Resistance Tester Model 6472
.
H (Z)
S (Y)
> 30 m
H
S
ES
E
and its frequency, U
H-E
> 30 m
Ω
mV
mA
AUTO
and its frequency).
S-E
35