ETCR ETCR2000+, Руководство пользователя

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VII. Measurement Principle
1. Principle of Resistance Measurement
The basic principle of ETCR in the measurement of resistance is to
measure the loop resistance, as shown in the figure below. The jaw
part of the Meter is comprised of voltage coil and current coil. The
voltage coil provides excitation signal, and will induce a potential E
on the measured loop. Under the effects of the potential E, the
current I can generate on the measured
loop. The Meter will measure E & I, and
the measured resistance R can be
obtained by the following formula.
2. Principle of Current Measurement
The basic principle of C + in the measurement of current is the
same with that of the measurement of resistance, as shown in the
figure below. The AC current on the measured
wire, through the current magnetic loop
and coil, can generate a induction
current I
1;
The Meter will measure I
1
,
and the measured current I can be
obtained by the following formula.
Where: n is the turn ratio of the secondary side vs. primary side.