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the grounding system to artificially create a loop for testing. The
following introduces two methods for measuring single-point
grounding with a clamp meter. This method can be applied to
the occasions that cannot be tested by the traditional
voltage-current method.
⑴
. Two Point Method
See the figure below, find an independent grounding body RB
(such as a nearby water pipe, building, etc.) near the grounding
body RA to be tested. Connect RA and RB with a test lead.
Because the resistance value measured by the clamp meter is the
series value of the two grounding resistances and the resistance
value of the test lead.
RT=RA+RB+RL
Among them: RT is the resistance value measured by the
clamp meter.
RL is the resistance value of the test line.
The resistance value RL can be measured with a clamp meter by
