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the smoke level and the air
temperature respectively in
the vicinity of the detector.
Thedetector’smicrocontroller
processes the two signals.
The temperature signal
processing extracts only
rate of rise information for
combination with the optical
signal. The detector will not
respondto a slowtemperature
increase - even if the
temperature reaches a high
level. A large sudden change
intemperaturecan, however,
cause an alarm without the
presence of smoke, if
sustained for 20 seconds.
The processingalgorithmsin
the multisensor incorporate
drift compensation. The
control panel must not have
a drift compensation
algorithm enabled.
The sensitivity of thedetector
is considered the optimum
for mostgeneral applications
since it offers good response
to both smouldering and
flaming fires.
Note: in situ testing of
the multisensor should be
carried out as for smoke
detectors.
XP95 MULTISENSOR DETECTOR
XP95 Multisensor Detector Part Number 55000-885
OPERATING
PRINCIPLES
TheXP95 multisensor detector
contains an optical smoke
sensor and a thermistor
temperature sensor whose
outputs are combined to
givethe final analogue value.
The multisensor construction
is similarto that of the optical
detector but uses a different
lid and optical mouldings to
accommodate the thermistor
temperature sensor. The
sectionalview (Fig.15)shows
thearrangementof the optical
chamber and thermistor.
The signals from the optical
smoke sensing element and
the temperature sensor are
independent, and represent
Fig.15 Sectional view - XP95 Multisensor Detector