Resistance
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Measurements
IRMS: actual test current (rms value)
VRMS: measured voltage between substation ground and the auxiliary
electrode U (rms value).
This measurement represents a broad band measurement, that
is, it detects all frequencies, for example, the 50 or 60Hz mains
frequency. That way, possible dangerous voltage levels
between the U auxiliary electrode and the substation ground are
indicated.
Phase shift between VRMS and IRMS.
R(f): calculated ohmic part of earth impedance (narrow-band
measurement)
X(f): calculated inductive part of earth impedance (narrow-band
measurement)