Figure 9: Current reading using the current clamp
15
Attached Rod Technique (ART) (DET3TC)
It is possible to use this instrument to measure the resistance of a ground
rod without disconnecting it from the rest of the system, thereby allowing
normal operations within the installation to continue uninterrupted. This
technique is known as the ‘Attached Rod Technique’ (ART). Where the
means of grounding comprises multiple rods, this technique also allows
individual measurement of each rod.
Measuring ground resistance with the ICLAMP using ART
(DET3TC)
Figure 10: Connection for measuring three-terminal ground rod resistance
1. With the selector switch in the ‘OFF’ position, connect the instrument,
as shown in Figure 10 and close the ICLAMP around the earthing
conductor under test.
2. Set the selector switch to the setting marked ‘3P
’.
3. Press and release the TEST button [by pressing and holding the TEST
button, the resistance measurement will be continually updated and
displayed].
Installation
earthing
conductor
Current
clamp
Potential
spike
Earth system
under test
Current
spike
