Decision Value; Alarm Algorithms For Smoke Detectors / Detection Levels / Offsets - Panasonic EBL128 Planning Instructions

Panasonic Electric Works Nordic AB
MEW01090 Rev: 3
The following is valid for the analog smoke detector types 430x in NORMAL
13.1.3
13.1.4
Figure 16. The basic working principle for one analog smoke
detector ("sensor"). Sensor value, working level, week average
sensor value, fire alarm offset / level and service level.
"Sensor Information" is available via menu H4/U3. Via Win128 and a
PC connected to EBL128 you can get "Sensor Information" for all
analog detectors on the COM loop or an individual detector. For an
individual detector you can also get continuous information. Also via
the Web-server II 1598 you can get "Sensor Information" for all
analog detectors on the COM loop.
The smoke detector sensor values are presented as obscuration in %
per meter (%/m) and heat detector sensor values as °C.
mode.
In order to secure real alarms and reduce nuisance alarms, advanced
algorithms are used and a decision value is calculated, see below.

Decision value

The decision value is used to decide if it is normal state, pre-warning,
fire alarm or heavy smoke alarm. It is also used in the smouldering
smoke algorithm (see page 86). The decision value is calculated, see
chapter "Filtering algorithm, page 84.
Alarm algorithms for smoke detectors / Detection
levels / Offsets
Each detector uses an alarm algorithm and each detector has three
different detection levels for:
88
1. fire alarm
88
The fire alarm level for each analog detector (sensor) = the current week
average sensor value + a fixed fire alarm offset (value), i.e. when the current
EBL128 Planning Instructions V1.1.x
81