e1276e
22
Siemens Building T
echnologies
Cerberus Division
09.2000
4.6.3
Detection of smouldering fire in high rooms
In order that smouldering fires or smaller fires with weak thermal current can be detected
even in high rooms, a second or a third IR beam must be arranged at the assumed height
of the spread of smoke of a smouldering fire. This application can be useful for rooms
>6m in height.
3m up to 60%
Reflectors
of the room height
DLO1
191
Fig. 17 Detection of smouldering fires in high rooms on different levels
Examples:
Room height
(highest level)
lowest level
intermediate level
6m
12m
20m
3 – 4m
6 – 7m
6 – 7m
–
–
~12m
4.7
Guideline for distances between DLO1191 and reflector
Distance DLO1191
à
reflector
Types and number of reflectors
5 – 10m
10 – 30m
30 – 50m
50 – 65m
20 – 100m
Short distance 1 DLR1193
1 DLR1193
1 DLR1192
4 DLR1192
1 DLR1191
If a number of reflectors are used they must be arranged close together and in the form of
a square. Distances are approximate, i.e. they depend on detector and reflector toler-
ances and can easily vary by a few metres. The important thing is that sufficient signal
strength is achieved.
