Gigahertz Solutions HF32D Mode D'emploi page 13

Evaluating the different radio services
The displays of the meters of this series show the sum of the total
power density within the frequency range of the most common
digital radio services. This means for the often dominating
sources of DECT and GSM as well as analogue sources: Simply
take the readings and compare them to the building biology
standard values!
To be able to evaluate the different radio standards and transmis-
sion and modulation patterns with one single measurement tech-
nology, the following approach to compensate for these differ-
ences is recommended:
UMTS/3G, LTE/4G, WiMAX, DVB, WLAN
The modulation of these high-speed services includes high, nee-
dle-like peaks compared to the average power transmitted. Such
signals are referred to as "high crest factor" signals. Measure for 1
or 2 minutes by slightly panning the meter pointing to the direc-
tion of the main source, and multiply the highest value by ten for a
comparison with the building biology recommendations
you will find different telecommunication services being present at
the same time. With the help of the audio analysis
able to estimate how much of the total value shown is caused by
such high crest factor signals. Depending on the proportion to the
total signal, please apply the following "rules of thumb":
Low portion of "high crest factor signals" audible:
multiply display reading by 2.
~"Fifty-fifty"-ratio: multiply display reading by 5
Dominating "high crest factor signals":
multiply display reading by 10.
Taking into account the multiple external factors of measurement
uncertainty, this approach is perfectly adequate for an assess-
ment of the total pollution. The use of a frequency filter and ser-
vice specific correction factors will allow an increased accuracy.
Radar beams are emitted by slowly rotating antennas. Therefore
they are only measurable and audible for only milliseconds every
few seconds. Due to the extremely fast rise-time of the signal only
a rough estimation of the real signal level is possible:
Set "Signal" to "Peak". Take the highest reading of sever-
al radar beam passes displayed and multiply it by 10.
When using the HF38B, you can set the switch to "Peak
hold" and allow for several beam passes to establish the
equilibrium of charging and droop rate of the holding ca-
pacitor. The reading may take a few minutes to stabilize.
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Even if their standards specify far higher crest factors, the industry strives for
crest limitation for economic reasons, so that the resulting correction doesn't
exceed a factor of 10. For the time being with LTE a factor of 20 may still occur.
For TETRA a factor of 2, for WLAN ("standby-rattling") a factor 4 is enough.
Mind the internal noise level, where a correction does not make sense.
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Applies for HF35C and HF38B (sound samples on our homepage). When using
the HF32D, the approach would be to multiply the display value by 10 to be on
the safe side, especially at low levels and when DECT phones can definitely be
excluded as source.
© Gigahertz Solutions GmbH
Made in Germany
:
during full data transmission
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. Often
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, you will be
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