M ad e in Ge rm any
© Gigahertz Solutions GmbH
sionally over the year, as the situation can change over night. As
an example, a transmitter only needs to be tilted down by a few
degrees in order to cause major changes in exposure levels (e.g.
during installation or repair of cellular phone base stations). Most
of all it is the enormous speed with which the cellular phone net-
work expands every day that causes changes in the exposure lev-
els.
Minimum distance 2 meters
Due to the physics of wave generation it is not possible to reliably
measure the customary ”power density” (W/m²) in the close vicinity
of the source of radiation. For the instruments described here, the
distance should be in excess of 2 meters.
The nature of HF radiation requires a specific approach for each
- the determination of the total exposure to it and
- the identification of the sources or leaks for the pollution.
Step-by-Step Procedure to Measure the
Total Exposure
When testing for HF exposure levels in an apartment, home or
property, it is always recommended to record individual meas-
urements on a data sheet. Later this will allow you to get a better
idea of the complete situation.
Preliminary Notes Concerning the Antenna
As the LogPer Antenna provided with this instrument is shielded
against ground influences one should “aim” about 10 degrees be-
low the emitting source one wants to measure to avoid distortions
in the area of sensitivity transition (aim horizontally for moderately
elevated targets like masts of transponders).
The analyser suppresses frequencies below 800 MHz to avoid the
readings being disturbed by lower frequency sources. In order to
measure frequencies below 800 MHz down to 27 MHz the instru-
ments HFE35C and HFE59B are available from Gigahertz Solu-
tions. They come with an active horizontally isotropic ultra broad
band antenna from 27 MHz up to beyond 3 GHz, the UBB27.
Settings of the Analyser
The HF32D comes with ‚Range’ and ‚Signal’ already set to values
typical for the assessment of the impact of the HF radiation by
building biology standards.
The HF35C and HF38B feature additional settings as described
below:
At first set ”Range“ to ”1999
µW/m²“ resp. ”19.99
mW/m²“. Only if
there are constantly very small readings, switch to the next finer
range
6
. The basic rule is: as coarse as necessary, as fine as
6
HF38B – „Range“: When switching from ‘Coarse’ to ‚Medium’ for very small
readings, it could happen, that the instrument tolerance of +/- 3 dB full range is
absorbed. In this worst case there may be a factor 4 between the displayed num-
bers in ‚Coarse’ and ‚Medium’. Example: In ‘Medium’ you read 150.0 µW/m². If
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