5.5 The panning approach
When evaluating exposure limits, usually only the
maximum signal level
is
important. This maximum can be determined by using the so-called “panning
approach“, which is already established as a
legally binding means
of measu-
rement in many countries. Proceed as follows:
Choose the desired frequency range. In our example, we have already done so
(key 2). Activate HOLD mode (dot key) as described previously. Afterwards plea-
se also activate 3D measurement by pressing the 8 key. This will save you the
hassle of having to move the device around constantly in
all
directions near the
measurement subject.
Now, keep measuring until the value stops changing completely. You have now
determined the signal maximum at a particular position/location.
However, should you wish to determine the signal maximum in an entire room,
you additionally need to measure at every possible position. Walk through the
entire room, pay special attention to the walls and electrical appliances, where
you will often find the strongest signals due to electrical wiring. During measu-
rement, the displayed signal strength will rapidly increase, until at some point it
will stop changing and “freeze“ at the signal maximum. This can take several
minutes when testing an entire room. After completion of this procedure, the
maximum signal strength found in the entire room is shown on the display.
As field strength diminishes very rapidly with increasing distance (depending on
the source, r, r² or even r³), you can quite easily determine the exact location of
a signal source (the higher the signal level, the closer the source). Of course,
you will need to turn off HOLD mode in this case. Next, simply try to find the sig-
nal maximum in various rooms to get acquainted with the panning approach and
the importance of HOLD mode.
Now, of course your measurement result is not that useful if you cannot relate it
to any exposure limits. Until today this used to be very complex with the need to
browse complex tables and convert between physical units. A highly daunting
task for the novice and even for some experts. SPECTRAN offers therefore a
special and easy to handle mode for exposure limit calculation:
5.0 Your first measurement / Modes
Firmware V 1.0 / © 2005-2013 by Aaronia AG, D-54597 Euscheid, www.aaronia.com
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