Gigahertz Solutions HF32D Mode D'emploi page 13

To be on the safe side in this comparison you may multiply the
measurement by 4 and use the result as base value for the com-
parison. This is often done to make safe recommendations even
in case of readings on the low side despite still being within the
tolerance band. One has to consider, however, that this may also
lead to higher values than actually existent.
The ratio of minimum to maximum load of a cellular phone base
station usually is 1 to 4. At the time of measurement one does not
know the exact load. One way to overcome this is to measure
during low load periods (in the very early morning hours, e.g. from
3 to 5 am) and muliply the measurement by 4.
Special case: UMTS/3G and DVB-T: Measure 1 to 2 minutes
their incoming direction tilting the instrument slightly around it.
These special types of signals can sometimes be undervalued by
a factor of 5 by the analysers described here.
Special case: Radar for aviation and navigation. Radar beams are
emitted by slowly rotating antennas. Therefore they are only
measurable and "audio-analysed" every few seconds for millisec-
onds. This necessitates a special approach:
Set "Signal" to "peak". After a couple of radar beam passes
read out the highest number displayed. Because of the slow
repetition rate of the display necessary for all other measure-
ments, the numbers will vary considerably and will only be dis-
played for a very short period of time. When using the HF38B
set the switch to "Peak-hold" and allow for several beam passes
to establish the equilibrium of charging and drooping, which
may take a few minutes.
In most cases the measurement will be at the lower tolerance
band or in the extreme case even up to a factor of 10 too low
For a simplified measurement of UMTS/3G-, DVB-T and Radar
without correction factors, Gigahertz Solutions offers the profes-
sional HF-Analysers HF58B-r and HF59B.
Limiting values, recommendations and
precautions
The "Standard der baubiologischen Messtechnik" (Standard for
Building Biology Measurements), SBM 2008, classifies measure-
ments (per radio communication service), with a note of caution
"pulsed signals to be taken more seriously than continuous ones",
as follows:
Building Biology Recommendations as per SBM-2008
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Measurement will take longer because of the rapid fluctuations typical espe-
cially for UMTS.
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Please note that there are also Radar systems operating in the higher Gigahertz
range.
© Gigahertz Solutions GmbH
Made in Germany
Peak hold
Radar
Peak
Symbolic sketch
7
in
8
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