31
Measuring Earth Resistance Precisely
(Precise Measurement, 3-Pole Measurement Method)
Auxiliary earth resistance check
The FT3151 has a function for checking the auxiliary earth
resistance. Be sure to perform this check before measuring earth
resistance. The check result should be evaluated as follows:
The more the needle of the galvanometer deects to the left, the
higher is the auxiliary earth resistance. (If the needle remains in
the vicinity of the zero point, auxiliary earth resistance poses no
problem.)
1
Checking earthing condition of
auxiliary earthing rod H(C)
Set the range selector to H and press the
MEASURE button.
Verify that the needle of the galvanometer
rests within the green range of the S/H
CHECK mark.
2
Checking earthing condition of
auxiliary earthing rod S(P)
Set the range selector to S and press the
MEASURE button.
Verify that the needle of the galvanometer
rests within the green range of the S/H
CHECK mark.
1
2
3
4
5
6
7
Appx. Ind.