Hioki 3151 - 4.5 Measurement Precautions and Hints

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Chapter 4 Measurement Procedure
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4.5 Measurement Precautions and
Hints
(1) Using the auxiliary earthing rods
For 3-pole measurement, two auxiliary earthing
rods are required. Be sure to drive the rods
well into the ground to assure correct
measurement results.
(2) Earthing resistance of auxiliary earthing rods
When the earthing resistance of the auxiliary
earthing rods is not higher than about 10 kΩ,
the 3151 can carry out correct measurement.
However, especially when measuring low
earthing resistance values, high earthing
resistance of the auxiliary earthing rods can
impair measurement sensitivity.
To assure correct measurement results, be sure
to check the earthing resistance of the auxiliary
earthing rods by setting the range selector to
C
and P.
If the needle of the galvanometer is whithin a
green band of the scale, the auxiliary earthing
resistance is within 5 kΩ.