e1276e
8
Siemens Building T
echnologies
Cerberus Division
09.2000
3.4
Reflectors
Retroreflectors reflect the received light beam in parallel to the latter. For this reason the
reflector does not have to be installed thereby mandatory right–angled to the infrared
beam. Also vibrations and distortions of the reflector mounting wall do not cause any
problems. Another advantage is that any extraneous light is also reflected in its own di-
rection and consequently does not reach the receiver.
Reflector
Reflector
Reflector
max.
±
20
°
max.
±
20
°
Fig. 8
The reflector and reflector foil can be mounted inclined max.
±
20
°
in all
directions
DLR1191 prism
The retroreflecting prism has the shape of a pyramid whose lateral faces are formed by
isosceles orthogonal triangles. Light beams entering through the base are completely re-
flected twice on the lateral faces and reflected back through the base.
The prism is installed in a housing that is identical to the one used for the detector base.
The reflector is equipped with a reflector heater at the factory. If dew condensation is pos-
sible the heater should be connected to a 24V supply.
Light beam
Fig. 9
DLR1191 reflector and reflection principle
DLR1192, DLR1193 reflector foil
This foil consists of microprismatic elements that are formed by transparent, synthetic
resin sealed to a plastic substrate. In principle, the reflector foil has the same effect (func-
tion) as the prism.
3.5
Compatibility
Interactive
Collective
Fire detection system
S11
S11, MS9
Control unit
CS1140
CS11.., CZ10