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electrode), and finding out the potential difference V between E
and P (potential electrode).
Rx = V / I
6-2 Precise Measurement (Using Test Leads)
<1> Test probe connection
Stick the auxiliary earth spikes P and C into the ground
deeply. They should be aligned at an interval of 5 to 10m
from the earthed equipment under test.
Connect the green wire to the earthed equipment under
test, the yellow wire to the auxiliary earth spike P and the
red wire to the auxiliary earth spike C from terminals E, P
and C of the instrument in order. (three-pole (wire) method)
<Note>
• Make sure to stick the auxiliary earth spikes in the moist
part of the soil.
Give enough water where the spikes have to be stuck into
the dry, stony or sandy part of the earth so that it may
become moist.
• In case of concrete, lay the auxiliary earth spike down and
water it, or put a wet dust cloth etc. on the spike when
making measurement.
Summary of Contents for EY200
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