Brooks Firetracker FT128 CIE - Figure 36 an Example with the Smouldering Smoke Algorithm

Technical / Programming Manual
FT128 Rev 2.2
104
The smouldering smoke algorithm is dependent on and is always work in parallel with the
selected alarm algorithm, i.e. the smouldering smoke algorithm will affect the pre-warning
and fire alarm levels, see below.
If the decision value has been over the smouldering level for 7 minutes (1-2 in the figure),
the pre-warning and fire alarm levels will be lowered:
 The pre-warning level will be lowered to a level right between the original pre-
warning level and the smouldering level.
 The fire alarm level will be lowered to a level right between the original fire alarm
level and the pre-warning level.
If the decision value has reached the pre-warning level, but not the fire alarm level, after
additional 90 minutes (2-4 in the figure), the pre-warning and fire alarm levels will be
lowered again:
 The pre-warning level will be lowered to the original smouldering level.
 The fire alarm level will be lowered to the original pre-warning level.
If the decision value continues to rise, fire alarm will be activated (5 in the figure).
The smouldering smoke algorithm will be aborted and the pre-warning and fire alarm levels
restored to their original values if:
 The decision value becomes lower than the smouldering level.
 The decision value, after the 90 minutes, has not reached the pre-warning level.
 The decision value, after the 90 minutes and additional 120 minutes, has not
reached the fire alarm level.
The smouldering offset can be set in EBLWin for all detectors collectively, see Section
Alarm Algorithms, page 148.
Figure 36 An example with the smouldering smoke algorithm.
Figure 35 Explanations:
In this example, the week average sensor value has earlier been adjusted and is now "10"
(=1 %/m) at the "starting point", i.e. due to contamination the smouldering level has been
adjusted to "24" (10+14), the pre-warning level to "32" (10+22) and the fire alarm level to
"40" (10+30).
When a smouldering fire starts, the sensor values and the decision values will increase
very slowly from "10" and upwards.
1. The decision value has reached the smouldering level. A 7 minutes timer is started.