MEGABRAS MTD-20KWe - Equipment Operation Checking; 3. Equipment Operation Checking

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4. Technical Specifications
Application :
Measurement of grounding resistances (3
terminals), soil resistivity (4 terminals) and spurious
voltages present in the soil.
Resistance
measurement method
:
The equipment
injects an electronically stabilised
current in the soil, and measures, with high
preci
sion, the voltage developed in the soil by
means of that current flowing through grounding
diffusion re
sistances. Display shows the Resistance
value.
Immunity to interference :
Operation frequency: 1470 Hz
This operation frequency complies with the
equation:
Where:
fg = frequency of the current generated by the earth
meter.
n = integer number.
fi = industrial frequency (50 or 60 Hz)
The compliance with this equation implies that the
operation frequency will not coincide with any
harmonic of the industrial frequency, in order to
minimise the effect of parasitic currents present in
the surveyed soils, by means of the use of
appropriate filters.
Operation as a voltmeter :
In the voltmeter function, the equipment operates
as a CA conventional voltmeter, making it possi
ble
to check the presence and to measure volt
ages
generated by parasitic currents.
Measurement ranges :
Resistances: 0-20Ω ; 0-200Ω ; 0-2000Ω and 0-20kΩ
Voltage: 0-200V∼
Accuracy : Resistances measurements
: ± (2% of the
measured value + 1% of the maximum value of the
selected range).
Voltage measurement
: ± (2% of the measured
value + 1% of end of scale value)
Reading resolution :
0.01Ω in the resistance measurement.
0.1V in the voltage measurement.