1. Description
The EM-4058 earth tester is a digital instrument that allows to measure
the Earth resistance and Ground resistivity (using Wenner's method), as
well as to detect parasitic voltages present in the ground. This instrument
is suitable to measure earth systems in power substations, industries,
distribution networks, etc., according to IEC 61557-5. It is also suitable for
soil resistivity measurements, in order to optimize the earth systems
project. It is fully automatic and easy-to-operate equipment. Before
starting each measurement, the equipment will check that conditions are
within appropriate limits and will notify the operator in case any
abnormality turns up (too high interference voltage, too much resistance
in test spikes, very low test current, etc). Then, it will look for the most
suitable range and show measurement results in an alphanumeric
display.
In order to conveniently test the earth system, EM-4058 allows to perform
measurements using the test current which frequency may be operator
selected (270 Hz, 570 Hz, 870 Hz, 1170 Hz or 1470 Hz). On one hand,
the lowest frequency will allow to analyze the earth system behavior
related to fault currents of industrial frequency, while on the other hand,
the measurement performed with the highest frequency will best show the
behavior in connection with electrical currents caused by lightning and will
offer a very high immunity related to interference voltages that are usually
present in soils, specially near substations.
The instrument has four ranges that are automatically selected, covering
measurements from 0.01 Ω up to 20 kΩ, which allows to obtain very
accurate measurements for any kind of soils. During ground resistivity
measurement, the operator may indicate the distance between spikes in
order for the equipment to apply Wenner's formula and to show the
resistivity value directly. The EM-4058 has a Frequency Scan feature that
performs an earth resistance measure with all available frequencies
automatically and calculates, display and print the average result besides
the individual result of each frequency. Those results are saved on the
internal memory.
The equipment has a Bluetooth communication interface that allows
remote operation through a Tablet running the Android application. With it
you can save photos of the measurements and the GPS coordinates of
each. Also allows you to record voice annotations to each measurement.
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