Page 67 of 85
viasis 3003 user manual
via
traffic
controlling
gmbh
If the select switch is in position of the clock symbol the viasis works in normal mode. This
means the display parameters of the parameter sets 1 to 5 are activated by the time settings of
their weekly calendar.
In case the turn switch is in position 1 to 5 the display parameters of the selected parameter set
(see also chapter 6.3.1) are permanently active.
If the viasis is used at various, changing measurement locations with differing local speed lim-
its, the switch offers the possibility to change quickly the display parameters to appropriate
values of an another parameter set.
7 Technical and physical properties
7.1 Distance range
The detection distance range of all microwave detectors depends to a large extend to reflection
properties of the measured objects and interference properties of the near surrounding.
In common is valid:
As bigger, planer and orthogonal to the microwave beam axis the reflection surface is,
as longer is the distance range.
As less absorbing and scattering the reflection surface, as longer is the distance range.
As more other objects are in measurement beam, as shorter is the distance range (dif-
fraction scattering and foliage losses, shadow losses and so on).
Practically following factors have a reducing effect to the distance range:
High up to the edge of the driveway leading buildings, trees, poles, parked cars and
containers, which hamper the „free sight“ of the detector and/or lead to strong scatter-
ing losses.
Influence through weather, rain and snow lead to absorption losses of the radar
„Blinding of the detector“ through other moving objects as tree branches, persons,
resp. a reduction of the detection range by a too far in the leaving traffic directed radar
beam, see also chapter 5.2.
The above mentioned negative influences have practically a much smaller meaning than it may
seem now, but it makes clear that the reason for a too small distance range is only in rare cases
a deficient microwave detector.
In the free field the radar unit has a typical distance range of more than 120 m for genuine pas-
senger cars. Each viasis is tested before delivery regarding a sufficient distance range. For
trucks the distance range is about 50% higher due to the larger reflection front surface, for
motorcycles it is reduced to 50% and less.
The distance from where the numeric LED display can be read due to the chosen digit size is
also higher than 120 meter.
The highest distance range has a detector mounted in a height of 2 up to 3 meter to the hous-
ing bottom side. This offset from the ground results from the practically necessary small
inclination of the microwave antenna inside the display housing.
