Megger DET5/4D - CALCULATION OF RESISTIVITY

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CALCULATION OF RESISTIVITY
Assuming that the tests were carried out in
homogeneous soil the resistivity is given by the
formula:-
ρ
ρ
= 2πaR
where ‘R’ is the resistance measured in ohms, ‘a’ is the
test spike spacing in metres and ‘
ρ
ρ
’ is the resistivity in
ohm-metres.
For non-homogeneous soils the formula will give an
apparent resistivity which is very approximately the
average value to a depth equal to the test spike
spacing '
a'.
Fig. 19 Resistivity calculation Nomogram