ADInstruments AD6412 Manual De Usuario página 44

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So, if the measurement value of the Meter is smaller than the allowable value of the
grounding resistance, then the two grounding bodies are qualified for grounding
resistance.
(2) Three-Point Method
As shown in the figure below, in the vicinity of the measured grounding body R
independent grounding bodies of better grounding state R
First, link R and R with a test line; use the Meter to get the first reading R
A B
R
A
Second, have R and R
B
the second reading R
R
A
Third, have R and R
C
third reading R .
3
R
A
In the above three steps, the reading measured in each step is the value of the two series
grounding resistance. In this way, we can easily calculate the value of each grounding
resistance:
From:
We get:
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R
1
R
B
linked up, as shown in the following figure. Use the Meter to get
C
.
2
R
B
linked up, as shown in the following figure. Use the Meter to get the
A
R
B
R
3
R R R
1 A B

R
R R
C
2 B

R R R
3 C A

Manual de usuario AD6412
and R
B
R
C
R
2
R
C
R
C
AD Instruments
find two
A,
C.
.
1
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