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Precise Measurement for Earth Resistance
(Precise Measurement Method, Three-pole Method)
Measurement on concrete
Since concrete is conductive, auxiliary
earthing electrodes can be installed on
concrete.
Place an auxiliary earthing rod on
concrete and pour water over it, or
cover the auxiliary earthing rod with a
wet rag to form an auxiliary earthing
electrode.
If the earth resistance of the auxiliary earthing electrode is not reduced
by the above methods, place the optional 9050 earth net on concrete and
then position the auxiliary earthing rod on the earth net and pour water
over it. Before measurement, allow some time for the water to well soak
into the concrete.
As an alternative to the earth net, a metal plate or aluminum foil etc. may
be used. However, the earth net will provide better reduction in the earth
resistance of auxiliary earthing electrode.
Since asphalt is insulator, it is generally not possible to install the auxiliary
earthing electrode on asphalt. However, measurement may be possible on
asphalt that has water permeability.
9050 Earth Nets
www.calcert.com
1.800.544.2843
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