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figure below. Use the clamp meter to read the third data R3.
In the above three steps, the reading measured in each step is
the series value of the two grounding resistances. In this way,
each ground resistance value can be easily calculated:
Since: R1=RA+RB R2=RB+RC R3=RC+RA
So: RA=(R1+R3-R2)÷2
This is the ground resistance value of the ground body RA. In
order to facilitate the memorization of the above formula, the
three grounding bodies can be regarded as a triangle, and the
measured resistance is equal to the adjacent side resistance plus
minus the opposite side resistance divided by 2.
The grounding resistance values of the other two grounding
bodies as reference objects are:
RB=R1-RA RC=R3-RA
