Hioki 3151 - Page 42

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Chapter 4 Measurement Procedure
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If check results are unsatisfactory:
①
Drive the auxiliary earthing rods deep into the
ground and water the entire area with a
sufficient amount of water. Watering is usually
very effective in reducing the contact
resistance.
②
Change the location of the auxiliary earthing
rods. Choose a location with high humidity.
If the ground is volcanic rock or sand, the
supplied auxiliary earthing rods may not be
sufficient. In such a case, use a metal pipe or
other conductive object with a large surface
and bury it as deep as possible in the ground.
(3) Distance between earthing electrodes
As shown in the figure (a) on the next page,
when the distance between
E and C is l m, and
the distance between the
E and P electrodes is
varied (x m), the resistance of the earthing
body
E will measure as shown in the figure
(b).
Therefore, when the position of the auxiliary
earthing rod
P is closer to the earthing body E
or the auxiliary earthing rod C, a measurement
error occurs.