If you press the dot key for a second time, “HOLD” disappears again from the
MODE status field, and the HOLD mode is deactivated. For finding the absolu-
te maximum, the so-called “panning approach” is used:
5.3 The “panning approach”
When evaluating conformance of exposure limits, usually only the
maximum
signal
is considered. This value can be found using SPECTRAN and the Hyper-
LOG antenna using the so-called “panning approach”. The panning approach is
already
officially approved
in many countries. Application is as follows:
Choose the desired frequency range. In our example, we already did this
(GSM900 using the 7 key) and activate HOLD mode (dot key) as explained
above. Now turn and tilt the antenna slowly in
all
directions until the value stops
changing completely. You have now determined the signal maximum.
However, should you wish to evaluate the signal maximum in a room, you addi-
tionally need to take into account all locations. Walk through the entire room.
Measure especially in corners and near windows as these often produce the hig-
hest readings. During measurement, the maximum reading will also quickly
increase until it finally does not change anymore and “freezes” on its highest
level. When measuring a whole room, this may well take a few minutes.
Mostly, you will be able to find the highest reading by rotating the antenna to the
left or right by 90 degrees, as this corresponds with the alignment of the trans-
mission antennas.
As this antenna is directional, you can even do a bearing of the transmission
tower. However, often, this is only possible outside, as inside rooms, there are
too many reflections which produce erroneous bearings.
Now, just try to find the maximum in several rooms to get comfortable with the
“panning approach” and the important HOLD function.
Now, a measurement result is of course not too useful if it cannot be compared
to some kind of reference limit. Until now, this has been extremely complicated,
using complex tables and converting between units. An often exhausting task
even for some professionals, and particularly for the novice. Thus, SPECTRAN
offers a separate, very easy to use mode specifically for exposure limit calcula-
tion:
5.0 Your first measurements / Modes
12
Summary of Contents for SPECTRAN HF-2025
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