Gigahertz Solutions HF32D Mode D'emploi page 11

urements at different times of the day on working days and at
weekends. In addition it may be advisable to repeat them occa-
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
levels.
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 vicin-
ity 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
below the emitting source one wants to measure to avoid distor-
tions in the area of sensitivity transition (aim horizontally for mod-
erately 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
© Gigahertz Solutions GmbH
Made in Germany
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