57
What is the minimum distance I should keep from a wall or any other object?
Much depends on the type of material it is made, its density, how the environmental factors affect it.
If we take the example of an area monitor mounted on a wall bracket, we must also consider how the
latter will act on the signal that it is going to measure. If the wall was made of polystyrene, the control
unit could also be attached to it, but in reality the density of the materials with which the wall is made,
affects the signal.
It is also necessary to consider the atmospheric phenomena which, in conjunction with the structures
around the control unit, can affect the signal.
During a rain, with the slightly wet wall, will the reflected signal be the same? And if instead of just being
slightly wet it was completely covered with water? How does the refraction of the signal change?
It should be remembered that the area monitor measures a true value. If in a point the probe marks 10
V/m, it is because in that precise point there are actually 10 V/m, which is the result of the sum of all
the vector components, so both the direct and the reflected signals.
How do you know what is the most suitable point?
Good sense says that at least 3 to 4 meters away help minimize possible perturbations of the signal
that you go to measure.
The best approach would be to use a wide bandwidth meter and make pads in some parts of the area
chosen for installation, trying to locate an area where the signal is more homogeneous.
You do not just have to consider radio frequency though. Area monitors are programmed to send data
using a SIM card. So also the presence of the GSM / 3G signal is important. We recommend using a
cell phone to evaluate the presence and quality of cell signal.
