Advertisement
Available languages
Available languages
In fall 2008 the "Bund für Umwelt und Naturschutz Deutschland
e.V." (BUND) (environmental NGO) recommends a limiting value
of 1 µW/m² even for outdoor situations.
The Landessanitätsdirektion Salzburg (Austrian health authority)
proposed already in 2002 to lower the present "Salzburger
Vorsorgewert" (precautionary value) to 1 µW/m² for indoor situ-
ations.
Limiting values imposed by governments are mostly considerably
higher. There are indications of rethinking, though. The Internet
provides large collections of recommendations and data.
Note for users of cellular phones: Even below 0.01 µW/m² com-
munication is fully unimpaired.
Identification of the sources of pollution
Use the LogPer antenna for this job. It is shielded against ground
influences one should "aim" about 10 degrees below the emitting
source one wants to measure to avoid distortions in the area of
sensitivity transition (aim horizontally for moderately elevated tar-
gets like masts of transponders).
As a first step eliminate sources from within the same room (e.g.
cordless phones, wireless routers, etc.) Once this is completed,
the remaining radiation will originate from outside. For remedial
shielding it is important to identify those areas of all walls (includ-
ing doors, windows and window frames!), of ceiling and floor,
which are penetrated by the radiation. To do this one should not
stand in the centre of the room, measuring in all directions from
there, but monitor the permeable areas with the antenna (LogPer)
directed and positioned close to the wall
that the antenna lobe widens with increasing frequency. In addi-
tion reflections and cancellations inside rooms make it impossible
to locate the "leaks" accurately. See the illustrating sketch below!
Wand
Wall
Mur
Pared
Potentiell durchlässiger Bereich
Potentially permeable Area
antenna
For the definition and installation of shielding measures as well as
surveying their effect, professional advice is recommendable. An-
yway, the area covered by shielding material should be much
larger than the leak itself.
Audio Frequency Analysis
Many different frequencies within the frequency band between
27 MHz and 2.7 GHz, are being used by many different services.
7
Please note: In this position the readings on the LCD only indicate relative highs
and lows that cannot be interpreted in absolute terms.
© Gigahertz Solutions GmbH
Made in Germany
7
. The reason for this is
no!
potentiell
durchlässiger
Bereich
antenna
15
Advertisement
