Bosch INT-TX04, Руководство по эксплуатации, Страница: 23 / 94

Aspects of Infrared distribution systems
A good infrared distribution system ensures that all delegates in a conference venue receive
the distributed signals without disturbance. This is achieved by using enough radiators, placed
at well planned positions, so that the conference venue is covered with uniform IR-radiation of
adequate strength. There are several aspects that influence the uniformity and quality of the
infrared signal, which must be considered when planning an infrared radiation distribution
system. These are discussed in the next sections.
Directional sensitivity of the receiver
The sensitivity of a receiver is at its best when it is aimed directly towards a radiator. The axis
of maximum sensitivity is tilted upwards at an angle of 45 degrees (see the next figure).
Rotating the receiver will decrease the sensitivity. For rotations of less than +/- 45 degrees
this effect is not large, but for larger rotations the sensitivity will decrease rapidly.
45
45
90
Figure 4.3: Directional characteristics of the receivers
The footprint of the radiator
The coverage area of a radiator depends on the number of transmitted carriers and the output
power of the radiator. The coverage area of the LBB 4512/00 radiator is twice as large as the
coverage area of the LBB 4511/00. The coverage area can also be doubled by mounting two
radiators side by side. The total radiation energy of a radiator is distributed over the
transmitted carriers. When more carriers are used, the coverage area gets proportionally
smaller. The receiver requires a strength of the IR signal of 4 mW/m
2
per carrier to work
4.2
4.2.1
4.2.2
Language Distribution System Planning | en 23
Bosch Security Systems B.V. Operation manual 2013.11 | V1.4 |