AEMC 3640 - Page 37

Digital Ground Resistance Tester Model 3640 and 4610 35
ρ =
4πAR
1 +
2A
(A
2
+ 4B
2
)
2A
(4A
2
+ 4B
2
)
Lay outthe electrodes ina grid pattern(Figure 22) andconnect to the
Model4610asshowninFigure21.Proceedasfollows:
• RemovetheshortingstripbetweenXandXv
• Connectallfourauxiliarygroundelectrodes
Forexample,ifthereadingisR=15,
ρ
(resistivity) = 2πxRxA
A(distancebetweenelectrodes)=450 cm
ρ
=6.28x15x450=42,390Ω-cm
Ω
Press To
Measure
X-Z
Xv-Y
Xv-Y
ZYXXv
C1 P1 P2 C2
Fault
Hi Resistance
Hi Noise
GROUND RESISTANCE TESTER
MODEL 4610
AUTORANGING
REFER TO USER MANUAL
FOR FAULT WARNING LIGHT
EXPLANATIONS
!
®
INSTRUMENTS
R
B
XXvYZ
AAA
Figure 21
AAA
A
A
A
Figure 22