ORBIS
6
WHERE TO USE OPTICAL
SMOKE DETECTORS
Optical smoke detectors have always
been recognised as good detectors
for general use. They are regarded as
particularly suitable for smouldering fires
and escape routes.
The performance of Orbis optical
detectors is good in black as well as in
white smoke. In this respect Orbis is
different from traditional optical smoke
detectors which perform far better in white
smoke than in black.
Orbis optical detectors are also designed
to reduce significantly the incidence of
false alarms through over-sensitivity to
transient phenomena.
Orbis optical detectors are recommended
for use as general purpose smoke detectors
for early warning of fire in most areas.
ORBIS OPTICAL SMOKE
DETECTOR
The sensing technology in the Orbis
optical smoke detector is significantly
different in design from previous optical
detectors. A full description is given in
the section ‘How do orbis optical smoke
detectors work?’ but the advantages of this
system and its associated algorithms are:
• improved sensitivity to black smoke
• compensation for slow changes in
sensitivity
• extra confirmation of smoke before
the alarm signal given
The algorithms are used to verify signals
from the sensing chamber, to filter out
transients and to decide when the detector
should change to the alarm state.
All this combines to increase detection
reliability and reduce false alarms.
HOW DOES THE ORBIS
OPTICAL DETECTOR WORK?
Orbis operates on the well established
light scatter principle. The remarkable
optical design of the Orbis optical smoke
detector allows it to respond to a wide
spectrum of fires.
The sensing chamber of the Orbis optical
smoke detector contains an optical sensor
which measures back-scattered light as
well as the more usual forward-scattered
light. Sensitivity to black smoke is greatly
improved.
The detector is calibrated so that Orbis
is highly reliable in detecting fires but is
much less likely to generate false alarms
than earlier smoke detectors.
The stability of the detector–high
reliability, low false alarm rate–is further
increased by the use of algorithms to
decide when the detector should change
to the alarm state. This removes the
likelihood of a detector producing an
alarm as a result of smoke from smoking
materials or from another non-fire source.
Part Number ORB-OP-12001-APO
ORBIS
OPTICAL
SMOKE
DETECTOR
