Glossary - Bosch D296 Application Manual

18 en | Glossary

Glossary

beam-type smoke detector
A device that projectis a light beam from a
transmitter across the protected area to a receiver
that monitors the light signal. Smoke entering the
beam path decreases the light signal causing an
alarm.
detector coverage
An area in which a projected beam smoke
detector effectively senses smoke. This area is
limited by applicable listings and codes.
obscuration
The reduction of light's ability to travel from one
point to another due to the presence of solids,
liquids, gases, or aerosols.
range
The distance between the transmitter and
receiver. Also known as beam length.
receiver
A device, in a projected beam smoke detector
system, that monitors the signal level of the
infrared light sent by the transmitter.
sensitivity
The ability of a projected beam smoke detector to
respond to a given level of smoke.
sidewall
A wall parallel to the beam's path of travel.
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spacing
The distance between projected beam smoke
detector receiver and transmitter pairs.
spot-type detector
A device that senses smoke, heat, or both only at
the detector's location. These detectors have a
defined area of coverage.
stratification
An effect that occurs when air containing smoke
particles or gaseous combustion products is
heated by smoldering or burning material. The air
becomes less dense than the surrounding cooler
air and rises until it reaches a level at which there
is no longer a difference in temperature between
it and the surrounding air. Stratification can also
be caused by forced ventilation.
transmitter
A device in a projected beam smoke detector that
projects the infrared light across the protected
area to its associated receiver.
trouble
A service condition that needs to be corrected,
such as a broken wire, dirty detector, misaligned
detector, and so on.
Application Guide
Projected-beam Smoke Detectors
Bosch Security System, Inc.