e1276e
25
Siemens Building T
echnologies
Cerberus Division
09.2000
4.9
Minimum distances between two pairs of detectors
The monitoring beam must not be mounted closer than 30cm to the ceiling, walls, installa-
tions and stored material.
In order to prevent the mutual interference of two or more DLO1191 detectors where
there is an increasing distance between DLO1191 and reflector, maintain an ever-in-
creasing transverse distance between DLO1191 and reflector:
Distance DLO11.. and reflector
100
80
60
40
20
0
1
2
3
4
5
6 [m]
(m)
Fig. 20 Min. distance between two parallel IR beams
4.10
Beam spacing from the ceiling
In order that the IR beam can detect the smoke, it is normally mounted immediately be-
neath the cushion of warm air. The higher the room, the further away the DLO1191 and
the reflector should be mounted from the ceiling.
0.3
0.5
1.0
1.5
0
20
18
16
14
12
10
8
6
4
2
(m)
(m)
Room height
Sloping ceiling
(N > 0,2)
Flat ceiling
(N < 0,2)
Fig. 21 Distance from IR beam
⇒
ceiling
The steeper the gable roof, the greater the distance must be between the IR beam in
the gable and the ridge.
