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instrument is equipped with two shut up: voltage clamp and current
clamp.
As shown in Figure 2, potential E in the voltage-clamp is
excited in the measured and cause current I in the circuit. And the
current in the clamp can be measured. Using Ohm's law: R = E / I,
the value of R can be obtained.
Figure 2
The measuring principle
2
、
Multi-polar parallel grounding resistance measurement
Multi-point grounding system (such as the transmission tower
grounding system, grounding cable communications system,
certain buildings, etc.) grounds through the overhead ground wire
(shield communications cable) connection, as shown in Figure 3:
Figure 3
The two gaps of the clamps which are properly plugged in the
jacks are clamped on the grounding wire with distance of 30cm.
The two jacks are not interchangeable, the equivalent circuit shown
