Smoke Alarm User Manual

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Note: This document is based on the recommendations of BS5839 Part 1: 2002. It is intended only as a guide to the application of fire detection systems.
Reference must be made to relevant national and local standards.
2251EM PHOTOELECTRIC SMOKE SENSOR
The 2251EM photoelectric smoke detector combines a state
of the art sensing chamber with microprocessor control
and sophisticated processing to eliminate transient noise
conditions thereby giving reliable fire detection whilst
minimising unwanted alarms. It is approved to a range of
sensitivities, permitting the detector to be configured to match
the application environment.
The 2251EM includes algorithms, which compensate for
a slow build up of contamination such as dust, within
the sensing chamber. Once the detector has reached its
maximum compensation level, a signal can be sent to the
control panel to indicate the need for maintenance.
Tested and approved to EN54-7: 2000 by LPCB
Specifications
Height: 45mm in B501 Base
Weight: 102g excluding base
2251TEM PHOTO–THERMAL SENSOR
The 2251TEM multi-criteria fire sensor incorporates an optical
smoke-sensing chamber and thermal-sensing elements
combined with microprocessor control and sophisticated
processing to eliminate transient noise conditions thereby
giving reliable fire detection whilst minimising unwanted
alarms. It can respond either as a smoke detector, or a rate of
rise heat detector or, using special algorithms combining both
elements to provide improved reliability of detection.
The 2251TEM is an environmentally friendly replacement
for an ionisation detector, providing rapid detection of
fast, flaming fires without incurring the significant end-
of-life disposal costs associated with products containing
radioactive material.
The 2251TEM is approved to a number of sensitivity settings:
Three Photo-Thermal and two Auto-Adjusting, which slowly
adjust the detector’s sensitivity to match short term changes
in its environment, thus reducing the potential for nuisance
alarms. In addition, it is possible to detect an alarm from heat
only, for day/night operation for example.
Similarly to the 2251EM, the 2251TEM includes algorithms,
which compensate for a slow build up of contamination,
such as dust, within its optical sensing chamber. Once the
detector has reached its maximum compensation level, a
signal can be sent to the control panel to indicate a the need
for maintenance.
Tested and approved to CEA 4021, EN54-7: 2000 and EN54-5:
2000 (Class A1R) by LPCB
Specifications
Height: 45mm in B501 Base
Weight: 115g excluding base
System Sensor Intelligent Product Range