Gigahertz Solutions ME 3851A Mode D'emploi page 12

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Conversion table nT to mG >>> see back cover.
Frequency Analysis
AC fields are not only defined by their field strength, but also by the
frequency with which the polarity of the field changes. Your instrument
can separate the following common frequencies and frequency bands:
5 Hz to 100 kHz (ME3951A: 400 kHz):
Not recommended for hands-free measurements.
16.7 Hz: Overhead railway wires in Germany, France, Norway, Aus-
tria, Sweden and Switzerland.
50 Hz to 100 kHz (ME3951A: 400 kHz)
Electric power grid and its harmonics.
2 kHz to 100 kHz (ME3951A: 400 kHz)
Artificial Harmonics / "Dirty Power" above 2 kHz (e.g. from many AC-
adaptors, dimmers, TV-sets). Corresponds to band 2 of the Swedish
TCO guideline. A factor 10 lower safe limits are recommended for
this range!
Note: due to higher1/f- and white noise, tolerances of the filters and
micro movements of the instrument as well as frequencies beyond
the filter ranges, the reading in the position 5 Hz to 100/400 kHz can
differ from the sum of the filtered readings.
AC Output
For a more detailed analysis of the different frequencies, a spectrum
analyzer can be connected directly to the AC output of the field me-
ter. At the AC output a DC offset of maximum 50 mV is applied. It is
standard in oscilloscopes and spectrum analyzers that this DC offset
is usually suppressed by a capacitive coupling. In case the peripheral
analysis instruments are connected to the power grid including a
grounding conductor, the grounding of the field meter should not be
connected in order to avoid ground loops!
The bandwidth of the AC output is limited to 30 kHz at full-scale.
From 30 up to 400 kHz, it will be consistently descending down to
1/20 of the maximum reading. Since the field strengths in home and
workplace settings under most circumstances are within this range,
this output can actually be used up to 400 kHz.
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