Measuring Resistance Of Ground Electrodes (62% Method) - AEMC 4500 User Manual

X Y Y Y"
X
Figure 20
Measuring Resistance of Ground Electrodes
(62% Method)
The 62% method has been adopted after graphical consideration and
after actual test. It is the most accurate method but is limited by the fact
that the ground tested is a single unit. This method applies only when
all three electrodes are in a straight line and the ground is a single elec-
trode, pipe, or plate, etc., as in Figure 21.
Ground
Ground
Strip
Strip
Ground Rod
Ground Rod
Figure 21
Digital Ground Resistance Tester Model 4500
Z
Y' Y Y''
X-Y Distance
X-Y Distance
X
X
v
Y
20 200 2
2 10 50
2 20
Z
TEST TEST CURRENT RANGE
Y Electrode
Y Electrode
Alligator Clips
Alligator Clips
Z
Effective Resistance
Effective Resistance
Areas (No Overlap)
Areas (No Overlap)
Reading Variation
Reading Variation
Z Electrode
Z Electrode
29