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Precise Measurement for Earth Resistance
(Precise Measurement Method, Three-pole Method)
2.6 Precise Measurement for Earth
Resistance
(Precise Measurement Method,
Three-pole Method)
WARNING
This device can output a voltage of approx. 30 V.
Although the device has a dust-proof, jet-proof and
water-proof structure, the device should always be
dried before using it for measurement so as to avoid
electric shock.
CAUTION
Do not connect the test leads if any foreign material
remains inside. It may cause failure.
There are two types of measurement method for earth resistance:
precision measurement method (three-pole method) and
simplified measurement method (two-pole method), and the
precision measurement method (three-pole method) is the basic
measurement method for earth resistance.
The simplified measurement method is used when measurement
cannot be performed by the precision measurement method.
The precision measurement is performed by inserting two auxiliary
earthing rods into the ground as shown in the figure on p.38.
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